There's been a couple threads here and news stories as well about phony instructors out in Lake County. I think some arrests have been made but a ton of people who used one of the phonies were given letters to come in with a redone training cert or lose their licenses, although technically the students could be charged with a felony if they knowingly skimped on the training. Long and short of it is people were paying for courses that did not meet the legal minimums, even though the certificates claimed otherwise.
This is probably tied to that. Either they're still investigating or they are doing due diligence on the instructors whose certificates applicants are proffering. As to whether this is mandatory I'm going to go with probably. Although Ohio is a shall issue state, that's only when the sheriff is satisfied that the requirements set forth in the statute have been met. The sheriff has the inherent authority to make sure he's been given a legitimate certificate.
Never ask if you can carry at a non-posted place, but always ask why you cannot at one that is!
Just because they offer call ahead seating doesn't mean you call ahead for carry permission.