MR-9 Battery Adapter on a Canon F-1n

hi! just recently bought a mr-9 battery adapter for my canon f-1n. I also bought a sr-43 battery as specified in the description of the mr-9 packaging. once it arrived, i tested it and i cant see the needle metering anything if below iso/asa 1600-3200. additionally, i can only see the needle if i’m at around 1/125 or 1/60 or below. i also tested the recommended setting of battery checking (iso 100, 1/2000 ss) it did not work. But if i put my iso to 1600 or 3200 i can see the needle moving if i use the battery check switch. I tested out also the camera with a px625 1.55v and the meter is working like i can see the needle at every iso/asa from 25-3200. just wondering if any other users of mr-9 battery adapter or users that used mr-9 on their canon f-1 if you have encountered this problem? i’m quite frustrated atm because i waited for the mr-9 adapter for quite a while and this was the result when i tested it out hahaha.