Unfixable Desync?

[jerminatrix 0]

I'm desyncing on every server after about 20 seconds of standard play. Both Community and Official servers. I used Xbox double NAT test to find out that I did have a double NAT. I fixed that by connecting to my router. I cleared the game cache, deleted and reinstalled the game, connected directly to the gateway and verified the NAT issue was resolved, reset the MAC address both automatically and manually and forgot/reconnected to the router. Nothing is working. I have also called my ISP to reset my system and I factory reset my gateway. I also connected through a hotspot on my phone. Nothing worked. Help!

[nemorus 271]

If isp is of low quality or if there's some kind of malfunction of it it will be a constant problem. I had similar annoyance to solve few years back. Changed internet type, all wiring, techs confirmed it - and its fine since then.