@casino Originally you reported that the problem was only for your PC, not on any other type of device. And that was why you suspected that it was an outdated Windows XP problem.
Admittedly there is a problem, but we have to identify where the problem is first. The problem cannot be fixed until the root cause is found.
I have to say that this is not a router problem by itself. Because if it is a router problem by itself, then all of our users will be complaining madly. And since we are not able to reproduce the problem, there’s no way to find a “fix”.
Because originally it was a problem only for your PC, and now it occurs on all of your devices, something must have changed from then to now. Most likely, it has something to do with your network (Internet Service Provider), or has something to do with your device(s) in particular.