My friends in Aternos Java-Bedrock Crossplay Server cannot break the blocks!

My friends in Aternos Java-Bedrock Crossplay Server cannot break the blocks! I's annoying for me and my friends. They join my server and I have only operator success; I try many my different things to resolve this like making the online mode on by selecting the cracked option and also, I use different settings but still issue is not resolved, mt friends have member access so they can attack, kill mobs and do other things etc but they cannot break the blocks it's annoying. Can you resolve the issue of my server.

How?