Can't enter 12:12:52 in calc cell

users
#1

I make a new spreadsheet, formatted A1 as hh:mm:ss, tried to type "12:12:52".
After the second colon, the contents change to 12 (the one is overlapped by another character).
Version: 5.1.4.2
Build ID: 1:5.1.4-0ubuntu1
OS: lubuntu 4.4

#2

Win10 Version: 5.0.5.2 no problem

#3

This was a known issue tdf#97191
<https://bugs.documentfoundation.org/show_bug.cgi?id=97191> introduced
with support for emoji. The :10:, :11:, and :12: text sequence would
convert to their Unicode clock-face glyph:

U+1F559 CLOCK FACE TEN OCLOCK -- :clock10:
U+1F55A CLOCK FACE ELEVEN OCLOCK -- :clock11:
U+1F55B CLOCK FACE TWELVE OCLOCK -- :clock12:

The autocorrect emoji entry sequence for the clock face entries has been
changed for the 5.2.2, 5.3.0 builds but did not make the cut for the 5.1.6
release.

But, simple to work around in 5.0 and 5.1 releases by removing the entries
in the autocorrect table. Standard menu, Tools -> AutoCorrect ->
AutoCorrect Options -> Replace tab

Locate, highlight and delete the entries for :10:, :11: and :12: and OK out.