Originally entered by Bernard T in issue #31974:

"I would agree that this has morphed from the
original issue into
something else that is more difficult to
reproduce. However,
description and symptoms are exactly the same.
I find it hard to reproduce myself because at
present I am not
switching projects that often.
One additional observation could probably explain
why this happens:

When I opened an alternate project today after a
long time, one file
system was mounted in explorer as "Duplicate " +
<original file system
name> although it was NOT duplicate except the
last directory name in
the path. Files in the editor also had the
"Duplicate " prefixes in
the tabs. Without making any changes, I re-opened
the project and the
"Duplicate" file system was mounted normally.
However, the code
completion did not work any more."


Because the issue #31974 was always reproducible
and this issue is hard to reproduce, I have
created this issue with lower priority.
As for me, I have reproduced the state when
explorer showed "Duplicate" filesystem, but code
completion databases weren't deleted as mentioned
in #31974