Different effects and onset from 2C-B

Hello! A strange thing has been happening recently.

The first two times I took 2C-B I was already feeling effects after 30 minutes to 1 hour, the visuals were colorful and waving and it made me laugh to the point I wasn't able not to laugh in front of people.

The third time I took it, I was only feeling subtle effects (increased empathy but not willing to laugh) and after 4 hours I decided to go home because I felt disappointed. While I was coming home I noticed I had thought loops and even fractal-like visuals with color enhancement, similar to the effects I usually have on acid. Thoughts were deep but not funny like the previous time.

The last time has been the same as the previous one. I took only half a dose (while the other times I took full doses) and after 4 hours I thought "well, half a dose was too little to feel any effects". After 5 hours, it kicked in! And it was as strong as the previous time! Thoughts were deep and strange instead of hilarious. Everything breathed and the thoughts I had were strange and serious.

Have you got any explanation for this? While the difference in the subjective effects could have been caused by set (and maybe by setting too), the fact that 2C-B took 5 hours to kick in seems strange to me.