we recently updated our jira (software 8.12, core 8.12 and service desk 4.12).
since then, in service desk tickets eg. bugs, the description field and the comment fields are showing strange behaviour.
- The field is there, but if writing text to it, the text isn't shown to the user.
- if clicking the edit-pen
- already inserted text isn't shown
- the switch between Visual and Text is grayed out
- the field gets a blue border

- if clicked into the field, the inserted letters are interpreted as shortcut, opening other functions of jira like "Assign to:"
Problem appears only on the Service Desk Projects. In Software-Projects it works.
Screens, field definitions, permissions,... havn't changed. Thinks worked fine before.
Can you please help me, finding the problem?