Slow unstable power from wall outlet

Hi! I’m staying in a sharehouse and having a lot of trouble with the electrical outlets.
My Mac and phone charge fine everywhere else, but only work sometimes in my room.
I often have to plug and unplug a few times, and the socket usually charges much slower, or not at all.

The owner says the outlet is fine, but I’m pretty sure something is wrong with the power.
Has anyone had a similar experience? Is unstable electricity common in older buildings in Japan?

I’m guessing fixing the socket would be expensive since it might require new wiring.
Is there anything I can do on my end, like a specific charger or adapter that works better, to reduce the issue?

Currently I've tried native mac charger 96W, generic phone charger and an ANKER 100W charger

by onlo