Sent out my package via USPS on 5/5/21, was received by USCIS the morning of 5/7/21, and just saw the pending debit to my account for the cashed check today, 5/21/21, exactly 14 days later.
No text message confirmation yet, and the NOA1 didn't show up in this morning's Informed Delivery, but I expect it should be on its way!