Hi @User - thanks for the post!!!! I was not sure what you are saying. The ANT cell is in the LEF file:

MACRO ANT

They shouldn't have to be in the liberty file as it is really not characterized or affects timing. We have never seen it in a .liberty file in our experience with cells before working ARM, Synopsys, TSMC, as well. Have you seen it differently? The LEF file also is annotated properly (and tested through pnr) with :

ANTENNADIFFAREA 
ANTENNAGATEAREA

to work with pnr. Thanks again! Let us know.