Camera won't connect to mesh router

[millaroo2500]

I have a Deco mesh router and the cameras won't connect after numerous tries.  Also no success with the "WI-FI Scan" on the app.   I would rather not but I have a base station from my old system (VMB 4000) that I could use as a last resort.  Is there a limit on the amount of cameras you can connect to that base unit?  I thought I might have read somewhere that it was a four device limit.  I want to connect six cameras all together.

[Streak2]

At what point is it failing?

There is no limit to the number of cameras you can connect to the base.