PDO exceptions on space homepages after upgrade to 2.22

After upgrading to OA 2.22 our space homepages are giving PDO exceptions. One function that is triggering the exception is oa_core_space_sections() in oa_core.util.inc – the function is being passed a string value of 'All' for the $gid parameter which is causing the DB query to fall over as it is an integer column in the database.

I've had a look at the contents of the form state (?) and on the space homepages the og_group_ref_target_id is set to the string 'All' (rather than an integer ID) which seems to be the root cause of the exception. Likewise oa_section_ref_target_id is also set to 'All' on another space homepage which is causing a similar issue.

Any ideas what is going wrong here? We're using PostgreSQL as the backend, but I'd be surprised if this would make any difference here.

Is it possible our site is somehow set up wrong so these values of 'All' are appearing when they should be integer values instead?

Thanks,
Ben