@Dusan_Krehel: Hi, please always include steps to reproduce and an example in Phabricator and fill in all fields of the template instead of deleting the template. Thanks.

Example here: Word'''B'''''',''' Word Word'''2'''

The current output is not wrong as the input is non-deterministic. That's the problem of wikitext - it has no exact specification.

Of course you can put <b>e</b><b>v</b><b>e</b><b>r</b><b>y</b> single letter separately into bold markup. But that makes no sense to me.
You can write Word'''B,''' Word Word'''2''' instead. Declining this ticket.