maybe contact Mikrotik directly through
support@mikrotik.com to see if this is expected? Also are you able to see it if you look through the terminal?
I feel that I could either take or leave the CCQ reporting, all I use it for is a quick look to confirm if a p2p or p2mp link is working correctly, if you are using this for AP's only you will get a lot of false negatives as phones and other things that connect but arnt being used will give off a low CCQ.
I would personally suggest using the staples of checking the TX and RX signal to see if the alignment is ok, checking the noise floor and the signal to noise to make sure one of your neighbouring radios hasn't jumped ship to your frequency as well as check the TX and RX packet and byte statistics, if there are a lot of tx packets, bytes etc in comparison to the RX you can see if you have had to retransmit a lot of packets and get an idea on if something is going on