I used deco m5 router fromm my provider, but changet it to archer ax53 to get 802.11 ax support. After that gog.com and galaxy stoped to work. Website not losding images, galaxy too + says im offline... Im tryed to change dns on browser, windows, router, tryed to change on/off all settings to check, but nothing helped. May be smbdy know how to solve the problem please? Cant play in coop or buy games now. even here i use phone with mobile internet...

I do not get it what the WLAN got to do with any website? This is a internal network in which most likely your PCs antenna could be incompatible. So you may change to a lower standard which is supported by your PC.

802.11 ax is a very new standard and only the newest MBs are compatible with.

You may try connecting your PC to a LAN and if the problem is solved it seems this is a internal PC issue.

Even on my phone if i connect through archer ax53 i have this problem. So this is router problem. And thanks, i understand what is 802.11 ax and what i need to make it work on my pc. but only gog and galaxy have this problem. No other websites or game launchers.

Then you should probably check your firewall settings. Apparently your modem or provider is a GoG hater or hated by GoG.

Weird story, really... so i have some interest into the solution.

I just do not get it why it should be a WLAN, issue. Most likely there is some settings screwed with GoG, but i can not say if this is happening internally (on your modem or your install) or externally (caused by some GoG server settings, apparently trying to use "the old modem spec" which is not working anymore). Basically, you and/or GoG will have to reset the "old settings", so the new settings will be attached correctly. I would reinstall Galaxy too and reset your browser cache on GoG.

-Check Firewall (if it is blocking something)
-Reinstall Galaxy and reset settings
-Reset Browser cache