AHI Level increase

At my sleep study I was told my AHI level was 5.1 and would need to wear a cpap because I had triple bypass surgery one year ago. I've been wearing the cpap now for a little over 2 months but my AHI levels seem high to me. They are usually around 4.1 to 5.3 or more and last night was 6.1 with a mask fit of 100%. I know I'm new to this, but seems like those numbers should be much lower.

Are you sleeping well with the mask and machine or do you find you are spending some time awake with the mask and machine on.
Sometimes the AHI gets falsely elevated due to the fact that sometimes the machine can record some awake/semi awake breathing irregularities by mistake.
It can't tell if you are awake or asleep. It just measures air flow and it's common for our awake/semi awake breathing to be more irregular and the machine can get fooled.

You need to use available software to see which type of apnea event is being flagged.
https://sleep.tnet.com/equipment

It would help if we knew which machine and mask you were using so when you have time please add your equipment to your profile like I have mine.