@sarta, I see this:
Declaration of Jetpack_IXR_Client::query() should be compatible with IXR_Client #16865
followed by several instances of Cannot modify header information
. I’m wondering if your installation is corrupted.
To fix it, use FTP or your file manager to remove the Jetpack folder. Then log into WordPress and reinstall it, and reconnect it.
If the issue persists, please let us know.
@bestspeaker, if you are receiving the exact errors posted above, could you try the same steps? I’m basing this on the resolution in this Github issue:
https://github.com/Automattic/jetpack/issues/16857