Hi there @keletkezes
To check things out what I'd do is power down everything and restart all equipment from scratch. Check all connections too.
which router are you using? Can you try an alternative router? If you've had it a few years you might be able to negotiate a replacement with an updated model with PN. Tech support may offer you a replacement.
Next , if you have a master phone socket connect your router via the test socket and a micro filter after removing the faceplate.
Allow ten or fifteen minutes for the router to settle down then log into the router using an Ethernet cable connection and check that the user name and password have updated to your own username in the format "username@plusdsl.net" This should happen automatically but if it does not you will need to edit these settings. Then save them.
Hopefully your system will then be ok.
what might have happened? Well it's anyone's guess, but for example there could have been a short power cut or power surge at your property that you were unaware of. I've known this scenario send a router and a computer into a hissy fit , ruin its settings or even fry the router making it unusable. There are also other potential scenarios that could result in your symptoms such as faulty eldrtical equipment either in your property or nearby. For example microwave ovens are well known cause of problems.
Are you using any home plug units? If so remove them and see if your symptoms go away.
Let us know !
Good luck.
