(1) Unknown server error { "message": "invalid csrf token", "code": "EBADCSRFTOKEN" } Request: "POST", url: "/", status code: ""

[GWONG3]

I have recently upgraded my 2 pigallery2 containers (2 albums) from "latest" to "edge-alpine" in order to get support for HEIC format photos. One of the containers reported this error in red and not sure I can fix it. I have tried clearing browser cache as suggested from reading other threads but no luck....

(1) Unknown server error
{ "message": "invalid csrf token", "code": "EBADCSRFTOKEN" }
Request: "POST", url: "/", status code: ""

Thanks in advance!