Log Insight Regex

I need to filter out words using RegEx.  Using RegEx tool it is correct but Log Insight doesn't filter accordingly.

RegEx Filter:  ...-[a A][b B]

Phrases:

This is a test:  ght-ab   << filter out

This is a test:  tty-AB   << filter out

This is a test:  tty     << not fitlered

This is a test:  aah   << not fitlered

Any idea how to filter out entries with "xxx-ab" and "xxx-AB" ?  I need to create alert based on this.

Does Log Insight fully support standard RegEx or it's something else ?