Anyone else's tax refund being held because the IRS is investigating TT?

I never had an issue with my refunds and all of a sudden I get a letter stating the IRS is looking into my refund? I was advised that the IRS is investigating TT because of the additional Advance Child Tax credit. I reported the information correctly and claimed I did receive the advance credit and to pay it back. Is anyone else being delayed because of this? I cannot get through to TT, and every time I send a message it says a specialist will contact me, but I never get a call. What am I paying for?