Can no longer print #10 envelopes

[WorkzHard]

I've been printing envelopes without problem for years on my HP LaserJet printers.  This week, the envelopes print as if an 8.5 x 11 page has been loaded -- the address is on the top of the envelope.  I'm printing from Word, using the mailing/envelope function.  I'm loading the envelopes in the center of the manual feed tray, using the alignment guides for envelope.  Word is setup to format a #10 envelope, and also shows the same tray placement.  The printer prompts me to load a #10 envelope.  his is all I've had to do in the past, and I can't find any other setting to change.   Today I uninstalled and reinstalled the printer, but it didn't make any difference. 

Of note -- a few weeks ago I had label alignment problems, last week it was check alignment problems -- all things that worked fine until they didn't.  This printer is starting to feel psychotic.  When it works, it works well.  When it doesn't -- there's an hour of my day gone.

Thanks for any help.  For the time being I have a LaserJet printer and I'm writing envelopes by hand .......

[WorkzHard]

Solved.  Changed Paper Tray 1 to #10 envelopes (in addition to "load #10 envelope, which was already done.  Have never had to do this before, but I guess I do now.