Extremely slow editing calendar in Thunderbird CalDAV

Hello,
We’re seeing very slow ( 10+ seconds) behavior when editing a synced calendar in Thunderbird, accompanied by a massive spike in CPU usage
Reported in GitHub here - https://github.com/nextcloud/server/issues/47092#issuecomment-2371301337

I’m finding this issue happens with multiple NC instances on different servers after a fresh install. with NO Security & setup warnings.
Happens with PHP8.2 and 8.3( recommended )
Happens on instance running Ubuntu 24.04.1 LTS and Ubuntu 22.04.4 LTS

Happens on different version of Thunderbird client

Unlike with Thunderbird, we’re able to add items to Apple’s Calendar app without the NC php process CPU spike.

but have a strong preference for using Thunderbird.
It’s also the one recommended by NextCloud
Synchronizing with Thunderbird — Nextcloud latest User Manual latest documentation

any thoughts or ideas?

I think it’s similar issue to Calendar item updates are very slow

But deleting all Devices & sessions and using Application password did not change anything.

Please help, and thanks!

1 Like