I also met this annoying issue since v11 and can reproduce it with many (maybe most) of my fonts, except for a few (e.g., Fixedsys).

Tested with all the registry data removed and without any plugin.

For example, input “AAAA” before 2 or more tabs.
“AAAAtt+” is expected.
But the actual result is “At+AAAt”.

Or, double click a word, the following tabs will be inevitably selected.