Updating to LibreWolf 91.0.1 breaks KeePassXC browser integration

LibreWolf 91.0.1 (64-bit), librewolf-bin 91.0.1-1 from the AUR, with KeePassXC-Browser plugin.

Error message:

Cannot connect to KeePassXC. Check that browser integration is enabled in KeePassXC settings.

Clicking on Reload button:

Key exchange was not successful.