I tried to print a PDF with SumatraPDF v3.3.3 64-bit on Windows 10 Pro 21H1 but the printer asked for Letter paper, while I only had A4.
Then I changed the Windows Printer Preferences/Properties to inform Windows that I actually have A4 paper.
The I tried to print again, but the same thing happened.
I had to close SumatraPDF and then open it again (with the same document). Now it printed on A4.
This may be a Windows limitation, but I report it just in case.
So the point: changes in Printer Preferences are not used in SumatraPDF unless it is restarted.