cannot reach books folder

HI there,

i have setup ubooquity via Synology Docker i used the linuxserver/ubooquity which works great.

i also have setup a reverse proxy so i can acces it via internet.

i connect via HTTPS and everyting works as designed exept for Books somehow...

when i click books i get the page cannot be found message. but when i check the url its pointed to http://mysite/books/10754/ and when i manually go to https://mysite/books/10754/ the page works just fine... is there a place where i can correct the link ?