Low ish wifi signal

Hi, I have iPhone 8 for repair that has kinda low wifi signal. It gets our wifi with 3 bars, but it won’t get any other (every other phone gets another 4 wifi stations). Sometimes it gets one more, but nothing else.

I have tried replacing antena, but it is still the same.

Any ideas?

crwdns2893858:0crwdne2893858:0 crwdns2893862:0crwdne2893862:0

crwdns2894050:0crwdne2894050:0

crwdns2889612:0crwdne2889612:0 0
crwdns2892346:0crwdne2892346:0