There's a long standing bug in the provided Vim plugin which breaks the expected case insensitive behaviour of Vim's autocmd event's.
There is a Stack Exchange description of the problem here:
By using the autocmd group name "filetype", which has the same name as an autocmd "event", subsequent use of case insensitive events will try to allocate the command to the group created in the systemtap Vim plugin.
I discovered this when installing the "Development Libraries" group on Fedora 31 which includes the systemtap-devel package. After this, other unrelated Vim plugins broke.
I was not able to reproduce the failure here, but speculatively committed
a fix by renaming the augroup.