This is mainly related to updated legacy themes, but maybe this can be useful for some others.

If you notice something like this: 

you need to find styling for a tag and remove display: block; 

It is because core templates were changed to list-group version. 

It should look this way:

Found in:

RideBlue2 2.1.0 [for 2.3.1 only]

Fixed in: 2.1.1