Internet slowing down after repair and restart

hello! I don’t know if anyone else is experiencing the same issue, so I might as well share;

my new MacBook Air recently broke so I decided to get it fixed at my local Apple Store where they had to completely restart it. Since then, the new iOS 26 for the Mac has been put on it, and I brought all my new information from iCloud over to it. But the internet seemed to slow down or get overal worse whenever I try to use it.

for example, at my house it use to be on full bars but now it only has one everywhere I go in my house. This completely slows down my computer and I am not able to complete simple tasks.

also when I am at my school, which is a very old building and the WiFi can misbehave sometimes, it uses to be full bars but now has only been at 2 or 1. I am positive it has nothing to do with the routers because it is a recurrence everywhere I go, I just don’t know why.

having someone to tell me how to fix it will be greatly appreciated