We are having the SAME ISSUE this year!
This is our third year snow birding. We have done the same thing each year. We have our mail forwarded to my MIL's house.
Last year we get even local ad flyer's. THIS year hardly any mail has made it through. Two items were of great importance. One was our property tax bill from our town. NEVER received! Had to call to get info in order to pay on time. Second was an investment statement that comes once a year. Never received! Had to call to get info.
Most all other "important" stuff I have email notification.
Spoke to local and home post offices and they could NOT help me!