It is good to heck the account setup before assuming it’s just a normal fluctuation.
The combination of zero leads + ads not showing + the address/city disappearing from the LSA account is what stands out. If this account normally gets 7–8 leads a week, that’s enough of a deviation to investigate.
For an SAB, you need to check:
Whether the business is still verified and eligible for LSA
Whether the service area is still configured correctly
Whether the associated Google Business Profile has changed or lost verification
Licensing/insurance or other verification requirements
Whether the LSA profile is showing any new setup, policy, or verification notice
Whether the service area/cities were automatically changed or removed
Also dont immediately recreate the profile or start changing everything, though. First document what the account looked like before the change and compare the current settings. Making multiple changes at once can make it harder to figure out what actually caused the drop.
The address disappearing by itself isn't necessarily proof that SABs have been broadly restricted. Google has been changing how business/location information is surfaced in its local products. Also we need to check whether other SAB accounts are showing the same behavior before calling it a platform-wide update.
If everything is still eligible and the service area is intact, then look at the account's impressions/visibility and lead data to determine whether the problem is actually delivery or just a temporary demand/auction change.