Win10 (Java Edition) no longer sees XP networked game

Prior to 1.12.2, the Windows 10 computer could connect to an old XP game open to LAN. Now it doesn't. I'm not sure what the issue is or what other operating systems it no longer effects.

For clarification, it is not "Windows 10 Edition" - It's the same Java edition 1.12.2 on each PC.