Any way to differentiate seasonal shedding vs acceleration of MPB?

[frogger]

Been on finasteride for about 5.5 years now which has done a good job halting the excess shedding and stabilizing what I still had. Though for the last 2.5 months or so, my hair has suddenly been shedding at a drastic rate similar to (or even worse than?) pre finasteride and it aesthetically looks thinner than ever, a lot of the areas I had full coverage just a few months ago are suddenly noticeably thin and see through. I was told it is likely seasonal shedding and is only temporary. Though if anything, it just seems to be increasing. Wouldn't this be a bit long for a seasonal shed of this extreme to last? I don't recall even ever experiencing a noticeable seasonal shed in the past. I have made no other changes to my regimen. Is there any way to differentiate a seasonal shed from just a sudden rapid increase of MPB due to medication losing it's effectiveness or whatever other reason?