floccus: Chrome 68: Network error synchronizing

Software versions

• Browser: Chromium 68.0.3440.75 (Official Build)
• Nextcloud: 13.0.4 (Snap)
• Nextcloud Bookmarks app: 0.11.0
• Floccus: 2.2.8, 3.0.0-beta5

Steps to reproduce

1. Enter nc URL and credentials as prompted to create a new account
2. Click “Sync Now”

Expected outcome

Bookmarks to be synchronized successfully

Actual outcome

Error message: Network error: Check your network connection and your account details

Checking the network requests in the development console, I see a long series of requests to https://<URL_REDACTED>/index.php/apps/bookmarks/public/rest/v2/bookmark?page=-1 with 302 result and finally a failure: net::ERR_TOO_MANY_REDIRECTS

Here is a relevant part of the console output:

Nextcloud.js:411 GET https://<URL_REDACTED>/index.php/apps/bookmarks/public/rest/v2/bookmark?page=-1 0 ()
Account.js:168 Error: Network error: Check your network connection and your account details
    at NextcloudAdapter._callee14$ (Nextcloud.js:421)
    at tryCatch (polyfill.js:6900)
    at Generator.invoke [as _invoke] (polyfill.js:7138)
    at Generator.prototype.(anonymous function) [as throw] (chrome-extension://djejpebekaoommcjfeaiipdikmdjkblg/dist/js/polyfill.js:6952:21)
    at step (background-script.js:25144)
    at background-script.js:25144
Account.js:170 Syncing failed with Network error: Check your network connection and your account details

If I clear browser cookies, the sync succeeds once and on the next and subsequent tries the same error occurs.