Paragraph number placeables not correctly identified, Regex Match also does not work

Hello again,

Enjoying my long ride on Studio 2019.

3.1.1 Paragraph heading

In the placeable, I am getting it as two placeables 3.1 and 1, both being underlined. It should come as one placeable 3.1.1.

Regex match, I have it for 3.1.1.1 -- even Regex match suggestion is not working. 

([0-9])\.([0-9])\.([0-9])\.([0-9])   --->> $1.$2.$3.$4 (thought this would take care of 3.1 and 3.1.1 and 3.1.1.1.)

Looking forward to any help. 

Hope you are enjoying your Sunday! (I am -- with Studio 2019!)

Best wishes

Guru