Unfortunately, there just isn’t enough data for a confident assessment, but let me suggest a couple of things to try.
First, try removing the BRIDGE from the equation, and wire an ethernet cable temporarily directly to your CONNECT:AMP. If that fixes the issue, you may have an issue with the power supply on the BRIDGE, which are known to fail with variable power outputs at this point, given their age. You could potentially replace your BRIDGE with a newer BOOST, which was the upgrade suggested long ago. Or, you could just keep the Ethernet cable to the CONNECT:AMP. Or, replacing the power supply for the BRIDGE might work, but it’s a device that is stuck in S1,
You may also want to do a simple network refresh, by unplugging all Sonos devices from power, then rebooting your router. Once the router comes back up, plug back in your Sonos devices.
However, if neither of those work, I would recommend that you submit a system diagnostic, and call Sonos Support to discuss it, or post the number here.
There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.
When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.