Error setting up Inbox

Dear experts,
I’m unable to get the inbox of my user working. The sending functionality seems to work, though with a substantial delay.

Inbox doesnt load though, and throws the following error. What might I be overlooking?

Title
pull_from_email_account
Error
Traceback (most recent call last):
File “/srv/bench/erpnext/apps/frappe/frappe/utils/background_jobs.py”, line 97, in execute_job
method(**kwargs)
File “/srv/bench/erpnext/apps/frappe/frappe/email/doctype/email_account/email_account.py”, line 744, in pull_from_email_account
email_account.receive()
File “/srv/bench/erpnext/apps/frappe/frappe/email/doctype/email_account/email_account.py”, line 297, in receive
attachments = [d.file_name for d in communication._attachments]
AttributeError: ‘Communication’ object has no attribute ‘_attachments’

edit: I see multiple experience similar issues, e.g. Email Inbox not displaying any messages. · Issue #8741 · frappe/erpnext · GitHub

My situation looks similar. Where you got this log from? I cant find any E-Mail logs…