@Tagggart 

Does your printer have an Ethernet option? To see if the issue may be it working with the Deco have 2.4G and 5G the same name. 

What you can also try or test is to disable the 5G to see if the printer then stays connected.

If you enable the guest network I do not believe there is an option to allow the guest to talk to the main?

@Tagggart 

same problem tech advised me to change to wpa3 personal but now all devices having issues wow

@Jeromiks I figured out my problem.  Maybe this will help you.  My xfinity router was putting out a wireless signal.  It had the same name as my mesh network.  So, my printer was connecting with the xfinity router, but my computer/devices were connecting with my mesh network.  The firewall between them blocked any printer connection.  I changed the name of my xfinity router so I would know to avoid connecting anything to it.  Solved.