To whomever this may concern,
I am a leader to one of the top clans that resides in Diablo 4.
Our name is BlazedNDazed, and we are a Cross-Platform Community of gamers.
We are always Capped at 150 Members… 
We usually have someone messaging on Discord about being unable to communicate VIA clan chat. They can still message the Local and Trade. They can even whisper anyone they decide, they just cant communicate in the Clan Channel or Join Clan voice channel.
We have been playing around with this issue. So far the only solution we have come up with to fix the problem is to kick members from clan and re-invite them.
So far from what we can tell is that the only people that are having this issue are the ones that are freshly recruited. The problem is that we have a recruitment system in place. No one becomes a member without agreeing to the 2 conditions every member is is faced with. We don’t tolerate Toxicity in our Community. This forces us to leave people in the Recruit Status for a longtime until we can finally reach the Recruits and Disclaim the conditions.
Any Recruit we can reach immediately does not seem to have an issue. It is those that have been in recruit status for a minimum of 5 days at the very least.
We do things this way because it reduces toxicity in the Community and provides an inclusive, fun and friendly dynamic that people enjoy.
We are not going to promote immediately, we need to be able to identify who it is we need to properly recruit. The best way to keep a Community like ours flowing the way we intend is to weed out the toxic players before they have a chance to Greif.
Thank you for your time