exitmap checks lower amount of exit nodes than should be available

I've seen that in the past when doing bad-relay checks but stumbled over it now again: for some reason it seems exitmap is not checking as much exit nodes as it should.

I just started exitmap testing my DNS resolution module and our reachability scanner roughly at the same time but the difference in exit nodes checked is 1143 vs. 1325. Checking Tor Metrics at the same time indicates that 1325 is the correct number.

Our reachability check just takes all the exits with an "Exit" flag excluding the ones with a "BadExit" one.

exitmap finds only 1152 exit relays with exit flags to begin with it seems and mentions that additional 75 ones having a non-empty exit policy but no exit flag. Then after applying a bunch of filter conditions it lands at 1143.

Note: both tests build 2 hop circuits with the same first hop.