Hi @kinrad . Lots of users are having wifi problem with Sagemcom.
The following thread has suggestions from some users about connecting to Sagemcom.
https://community.tpg.com.au/t5/Modems-and-Devices/Disable-Access-Point-AP-isolation-also-known-as-C...
I couldn't find whether your printer connects to just one wifi band, or can connect to either. If only one, you have to disable band steering, set each band to a different name so the printer can connect.
Disable AP isolation so wifi devices can connect to the printer. An ethernet computer should not have a problem.
Suggestion to create a guest network for your printer.
Connect your previous router as an access point connected to Sagemcom. Printer connects to old wifi. What model is your old router?
