Are all the APs mapped to the Default WLAN group? You might have created a new WLAN group(s) and accidentally mapped it to some of the APs and now they are not broadcasting all the SSIDs because you did not check some SSIDs in that Group? Could you please check if that is causing this issue.
We're actual facing the same problem with ZF7962 and Software Version 18.104.22.168 build 16.
Configuration is exactly congruent to all the other APs. All APs are in the same Access-Point Group and have the same WLAN-Group mapped.
If Configuration is exactly the same in all the APs and if you have one or few AP's NOT broadcasting all SSID's as per config then you can try the following to isolate if it is ZD or AP related.
If config on ZD is all OK the you can login into AP GUI and check whether all SSID interfaces on AP are up or not?
If they are NOT then easy one is to JUST reboot the AP and see.
If that does not help then remove the AP from the ZD and let it rejoin the ZD as fresh AP so any temporal issue may go away. Please try this only if something goes wrong you can easily recover the AP and put it back to work.
You can also reboot the ZD during lean time if possible and this will make "ALL" APs reconnect and fetch configuration from ZD fresh.