FileBrowser config carries server.internalUrl http://filebrowser:80 (OnlyOffice fetched the public files address and got 403);
Nextcloud's DocumentServerInternalUrl gets its trailing slash (every save was lost: http://onlyoffice:80cache/...);
RestartStack("filebrowser") runs the R-1126 gate at once (files.<domain> was 502 for up to 5 min after the link switched).
Each red-proofed. MinAgent 0.158.1.
