Can methyl B12 have a dramatically stronger effect than cyano B12?

I'm trying to make sense of what I'm experiencing, but it doesn't make sense to me.

I (F25) have been on high dose oral B12 supplements for months, dr approved for physical and mental symptoms. I stuck with it, physical symptoms mostly went away, but horrible fatigue, depression, anhedonia continued. I asked for a blood test for potential causes because it was unbearable, but everything looked fine. ​

My old supplements were cyanocobalamin 1500mcg, which were effective in raising my B12 serum levels. Searched chewable tablets when I was running low and got some sublingual 1000mcg methylcobalamin tablets on Amazon, just to maintain my B12 levels. Bottle said holding under the tongue is best so I tried that, and within 10 minutes my fatigue and depression improved. Not back to normal but a big noticeable improvement. It felt like I snapped back into my body, like I was suddenly feeling present and my emotions were stable.

I'm looking for doctors opinions, not anecdotal experiences. Is it possible for a slightly different form of B12 to make such a big difference? Especially when serum levels are already good?