And here is the fix.
After the last update many users began to complain that they could not share their work rota anymore. We immediately started working on fixing this issue. Today, after one week of internal and beta testing, version 1.17.23 is rolling out to the whole auditory. We recommend updating your app to the latest version as soon as possible.
Unfortunately, because of technical reason, old links are not working anymore. Please share your calendar again after updating.
Check for updates!