Comment 8 for bug 1755140

I might have identified the root cause.

It seems that this happens when the heat template generator enabled file before changing CSS to SCSS (perhaps) is used and the heat-dashboard code is the latest master commit.

When I updated _1650_project_template_generator_panel.py to the latest version (from heat-dashboard commit 2cc00e8e40d5bc8536c9dff3ebe32424f3f5d96a) and reload the dashboard, Django workflow forms I mentioned in comment #3 started to work correctly. The containers panel also started to work correctly (bug 1755308).

According to this, it seems that 'enabled' file MUST be updated when upgrading from queens to rocky, so this must be documented in the release notes. Otherwise operators and packagers cannot find the root cause easily.
In addition, this means if you plan to backport the enabled file change to stable/queens the backport should be verified very carefully. (perhaps you cannot backport it to the stable/queens branch even if the queens release has a problem on embedded vendor files.)