Please refer to this URL on the Ask LibreOffice site for details.
Affects LibreOffice on Linux and LibreOffice Vanilla on OSX. (other OS's could be affected)
Thanks for the bug report. It looks like this is a duplicate of bug 83103.
I can see that it triggers starting from one character shorter numerals than the other one, but the cause must be fundamentally the same.
*** This bug has been marked as a duplicate of bug 83103 ***
*** This bug has been marked as a duplicate of bug 56258 ***