Hm that's a weird one.  I tried replicating it but wasn't successful:

Any chance you could provide access to a duplicate of the base with no data in it for me to poke at?  Pretty curious about it!

Sorry I got busy and neglected to reply - now I have a bit more time I tried investigating and I think I have narrowed down on the cause, and found a workaround.

I also tried creating a fake base with fake data to share with @TheTimeSavingCo , and could not replicate the issue. 

The data in the original post is synced from another base...We have one large base with volunteer data (call this base CRM) and this syncs one-way to another base which we use to manage the volunteer involvement in various activities and events (call this base PROGRAMS). Check out the same record in both places:

The two formula fields, 'InformalSalutation' and 'CityState' are getting an extra line added in through the sync. I notice that in the destination (PROGRAMS) base these fields have been converted to Long text, which seems to be causing the extra line:

I created a test formula field in the destination (PROGRAMS) base, exactly the same as the formula that was being synced, and it DID NOT create this extra line:

I tried pointing this formula at the synced field and it worked, so this would be an easier workaround than trying to rewrite the whole formula in the destination base.

Summary: When a formula field gets synced to another base, it is converted to a Long text field and adds an extra line in Gallery view cards.

Workaround: Create a formula field in the destination base, not in the sync source, to avoid this extra line. You can simply point it at the source formula field which synced and it should format correctly.