It is time for me to step out from the dark, after being a FFM for some years (too much work/too little time for Lotus passion) and pay back to this great community.
I would suspect your left front brake HOSE have delaminated inner wall material inside, creating a kind of unwanted valve-mechanism (unless you also changed the HOSE).
I had that issue in my (LHD GT3 1997) right rear original brake hose. It also took a while for the brake pad to retract from the brake disc, after releasing the brake pedal.
Cutting the old hose confirmed the situation.
Problem solved after changing to SS-braided new ones