Z3 wifi signal strength weak compared to Z2

[Doparull]

After replacing the broken back panel on a Xperia Z3 Compact, wifi signal strength is weak and unstable. Compared to a Z2, the Z2 finds 5 networks with a good connection to my home router, while the Z3 Compact only finds the home network with a rather low signal strength. Before repair, wifi was all fine on the Z3 Compact. Could something have happened during repair?

[Uliwooly]

@Doparull

You can get it inspected by your >>> Local support, you can also test it on >>> safe mode