MacBook Pro M3 losing internet connection on home Wi-Fi but works on other networks

this is NOT Apple support. No one here works for Apple. The Official Apple Support link is in the bottom left corner of every page here.

This is the Apple User-to-User Support Community, where users who may have faced and beaten problems like yours try to help each other, and any user who has something constructive to add chimes in.

By far the easiest way to cause poor performance, instability, overheating and crashing is to install ANY third-party speeder-uppers, Cleaners, Optimizers, or Virus scanners, Bit Torrent, or a VPN that you installed yourself.

¿Are you running anything like that?

Wireless diagnostics:

Hold down the Option key while you click on the Wi-Fi icon on the menubar to open up the tools for investigating and fixing Wi-Fi issues

First is "Open Wireless diagnostics", which opens the wireless diagnostics Assistant, but does not proceed.

There are about eight different things you can do from here, but the top-level is to choose Diagnostics off the Window menu, or simply click continue, to do a quick check for Gross misconfiguration or operating problems. Your Admin password will be required. If any recommendations are shown, you should consider then seriously.

Next is to hold down the Option key and click the Wi-Fi icon as before. The screen that opens shows operating parameters of your network. Screenshot, transcribe, or photograph the results and post back in a reply on the forums. Looks like this older one.

There is no overall "fix" because you are operating your Wi-Fi in your own "network neighborhood". Your are surrounded by wildly variable factors and signals that might make you specific reception better or worse. What you need to do is work with Users here to determine what is going on in YOUR specific situation, and move to make it better. That will take some research.

Wireless diagnostics:

Hold down the Option key while you click on the Wi-Fi icon on the menubar to open up the tools for investigating and fixing Wi-Fi issues

First is "Open Wireless diagnostics", which opens the wireless diagnostics Assistant, but does not proceed.

There are about eight different things you can do from here, but the top-level is to choose Diagnostics off the Window menu, or simply click continue, to do a quick check for Gross misconfiguration or operating problems. Your Admin password will be required. If any recommendations are shown, you should consider then seriously.

Next is to hold down the Option key and click the Wi-Fi icon as before. The screen that opens shows operating parameters of your network. Screenshot, transcribe, or photograph the results and post back in a reply on the forums. Looks like this older one.