Hi, I've been using Tixati for a long time, and some months ago I got my ADSL upgraded to 100Mbps fiber connection. When this happened, they told me I couldn't use my older, cheap but really good modem, (because it wasn't compatible with VDSL2) so they gave me a crappy Technicolor rebranded "modem" that's three times as big and has half the Wi-Fi power of my older one (luckly my PC is connected via Ethernet). Since then, the modem started repeatedly freezing every 15/30 minutes (the LEDs are all on like nothing happened, the control panel times out in the browser and I can only hard reboot it). Time passed and I found out that when I had Tixati turned off, the modem wasn't freezing, so I had a clue on where to find the problem. Yesterday, after digging in Tixati's forum, I read a suggestion for a similar problem that consisted in turning off DHT. I did and I solved the problem! Causing another though, because I really want the DHT to be on, I don't want to spend any money on buying a better modem (also because the ISP blocks some 3rd party ones). I was wondering if there was some way of "scheduling" the DHT to search & announce only every now and then (like every 10 minutes), because when I do that manually, the modem never freezes. If there's any better solution, please tell, every suggestion is nicely welcomed!

try using the newest alpha and see if you still have this problem.

https://testing.tixati.com/

I downloaded and I'm currently using the 2.44a4. Before that, the DHT was getting ~780 nodes, right now it only has ~500 and there's a lot less activity in the graphs, they're pretty empty. On the other hand, the modem still hasn't frozen, I'm currently seeding my torrents as usual. I'm going to keep using it fore a couple of days and I'm going to report here any update on the problem and any strange behavior. Thanks anyways for the help!

maybe look at the diagnostic graphs. they are under help->diagnostics.

I already took a look at the diagnostics, but found nothing as expected, because eventho Tixati causes the problem, the modem itself completely crashes, even turning off Tixati or the PC. Sometimes the WiFi disappears on the other devices, sometimes they say the modem doesn't respond, but in the logs and diagnostics, there's simply a moment where the connections begin to time out and that's when the modem freezes.

After some hours of testing, I thought I solved the problem, but some minutes ago the connection started slowing down a lot, then the modem crashed again. Before that, the DHT still showed about 600 nodes (which is lower that what I had with the stable version) and had less activity in the DHT graphs.

Finding specific information to diagnose/send would be helpful...
Regarding updates a5 is out.

Unfortunately you really can't help it. It is possible the modem don't handle UDP very well. I do know when I got "upgraded" and they took away my DOCSIS 2 modem to give me the "better 3.0 version" they had broken settings which crashed immediately. Luckily I wasn't down because the technician had a box of "old modems" in his truck. #5 finally took. I would suggest in addition to trying DHT off, turning on logging in your modem, then keeping the log page open in your browser as you use the Tixati. Try forcing TCP only in Settings for Tixati.
Checking if you could simply NAT forward or whitelist UDP traffic may help. This would be in your Advanced Settings for the modem.
Also would suggest at minimum getting a router behind your modem. OR turning on the mini firewall in your modem settings. You really don't want a windows machine open to the internet. Especially when you will have peers from all over the globe finding out you have at least 1 open port (for Tixati).

I really appreciate your suggestions, and I would love to follow them, but this modem has options like "Turn on / off WiFi 2.4GHz", "Turn on / off WiFi 5GHz", "Port forward", "Static internal IP" and that's it, NO other useful options like firewall, logging, no "advanced" settings (which should really be mandatory in modems). Also I tried using my old modem/router as a router (and AP) only, but it won't work for some reason (still I think won't fix, because the modem still wouldn't be able to handle that many connections).
I'll try the a5 to see if there's any progress. I'll also try to prefer (or replace) UDP with TCP in Tixati.

By the way this reply was mine, I just wasn't logged in...

The main reasons you get this "crashing" when dealing with UDP is because UDP is stateless, unless there's an initial connection via TCP for intance... you can have ancient firmware (have you tried updating firmware? or maybe spoof the MAC addy of your "new" modem by using the old working one) which tries to track connectionless traffic. You think your computer slows down. Embedded device like this will simply stop responding.

If it has a logging capability you can try capturing that log and sending it in here... OR if you want a reprieve maybe search for your modem online... see if there are other fixes, or a place to submit to THEM for updating firmware. ALL good OEMs should at least have a place for downloads :(
Very sorry but there really isn't anything else you can do to keep it from happening unless you default OFF everything.
If you use channels, keep DHT on for that. But you can change in settings the default setting for DHT transfers. Turn tracker torrents OFF and change trackerless to search ONLY decreases traffic.
Like you said TCP only torrent traffic will also lessen this, if this is the true problem, but you will have to suffer with less connections. Its recommended to make sure your incoming port is forwarded so anyone who CAN connect via TCP will connect.

If you've ever heard of wireshark you can also try to capture traffic at the moment of failure (you'll know by how the torrents react when it will happen)... it's also possible the ISP / bad actors can spoof traffic to you, which may also affect hardware like this.

Lots of options, please update if you attempt any of this. The more information we share the better we all become. D: