And 7 - 8 blocks during some hours.

In fact, as of writing this, it has mined 161 blocks in the past 24 hours, which should correct down to 144.

Since the algorithm (DAA) takes a block around 144 blocks ago into account, it's going to take a while for it to smooth it out. Block -144 was still affected by pre-fork fluctuating difficulty adjustment algorithm (EDA). Constant miner migration between BCH/BCC also isn't making it easy.

I'll give it a few days to stabilize.