@olivierlambert Hi, I really appreciate your time!
I'm using a US QWERTY keyboard on a 2-year old MSI laptop running Windows 11. I first noticed this issue a few weeks ago when I first deployed xo-server v5.151.0 / xo-web v5.152.1 built from your sources.
A little bit ago I actually tried this in Brave browser and using shift worked perfectly fine. Then I tried it in vanilla FireFox and it worked fine there too...
I daily drive LibreWolf, a security/privacy version of FireFox and I usually don't ever have issues with it but I'm gonna chalk this keyboard thing up to something related to that.
Sorry about that!