How do I reconnect MacBook Pro after router upgrade?

Hi All

So, I'm on Ziply Fiber. Been working fine for two years. Today I had an 'upgrade' of the router; new IP, new this and that... I have to reload all my devices w/ the new this and that including reconnecting my printer drivers as well.

I have a MB Air which I use for music but my main MBP is running OS 10.12.6 because...Adobe... :-) It's a 2015 Retina 13"

Chrome won't run on it any longer so I'm using Firefox and until I switched the router was working fine.

But, with the new router I'm getting grief. It's dog slow, it forgets bookmarks, blah blah blah...

I've flushed the PRAM, I've rebooted, I've tried VooDoo,... Chrome works great w/ MB Air running Sonoma! :-)

Any thoughts?

Thanks you guys... you're awesome!

g

[Re-Titled by Moderator]

Original Title: NewFiberRouter and Old MBP