I myself use a modern OS but some of my family members still stay on Snow Leopard because it's the maximum OS their old machines support (but run quite well).
Chrome reminds of the fact that it's not supported anymore every time you launch it and it is very annoying, so I made a modification of the app: the Info.plist that points to an shell script within Chrome.app/Contents/Mac OS that launches Chrome binary with
This eliminates the unneeded warning, but breaks the automatic logins. It does in fact save the password somewhere because after saving (for example) a facebook password in the modified version and then launching an unmodified Chrome logs you in automatically.
codesign -v on the modified app and indeed it was broken, so I created my own cert specifically for codesign and signed with it, but it did not change the broken behavior.
How can I trace the issue?