Brokerage Accounts Getting Closed - help!

Posting here because I am not sure where else to turn...

In the past 6 months, I have had accounts at Robinhood, Charles Schwab, and Fidelity all closed with no explanation. I wish I had some information to go off of as to why, but no one will share any information with me.

I am scared to death which account will be impacted next, but also have no idea where to turn.

My Robinhood account has existed for over 10 years, Fidelity for over a year, and Charles Schwab for close to 6 months.

I only traded in mutual funds and my only plan is to contribute to my roth and park a roll over IRA.

Does anyone have any insight on why this might be happening?

I pulled a Chex report and LexisNexis, but won't get results for a week or so. I have pulled Chex before and nothing was there...