A big distance between different RF transmitters is always better. Some also reported poor WiFi signal from the RPi5. As HiassofT and Da Flex have already tried to point in this direction.
2.4 GHz is a free usable frequency range worldwide (surely with some exceptions). Nearly all modern RF devices flooding the air with their signals. Bluetooth and DECT is also there. So you must try it to find if you run into issues. For example if you near of a microwave oven (maybe on backside of the kitchen wall with your RPi5) you have another potential issuer in that frequency range.
