Auto accident lawyer

I’m getting the run around with my lawyer and progressive I’m just trying to see if I’m overreacting, settled my UIM on 6/12/26 the “check” was sent 6/14/26 via UNCERTIFIED mail on 7/8/26 the excuse my lawyer ( paralegal) claims it was lost in the mail and a new one is being reissued on 7/8/26

In my opinion from everything I’ve read up on sending uncertified mail is a extremely high risk for the insurance company because there is no proof of it being sent

So my question is does progressive send checks certified mail or not