I'm Miles from the Social Care team at Shopify.
I'm glad to hear you've been able to reconnect the channels without further issue.
There are a couple of reasons the channels might be disconnecting.
Are your products within Facebook and Instagrams guidelines?
Are you an admin for the Facebook Page?
We have a great help doc that walks you through each step of setting up the Facebook Channel.
If you continue to see the channels disconnected, be sure to reach out to us so we can help troubleshoot further.
Have a great day!
None of those two options stated by you fits in my case.
I have my stores connected to Facebook/IG for at least a couple of months and they are totally different niches. I haven't made any changes that could also impact the guidelines.
The only different thing I did yesterday was to pause a third store I have in Shopify and add a password to the page, other than that I haven't touched anything.