Need "full seat" to access design tools on MY OWN Figma Slides. Unable to edit.

I was making a Figma Slides presentation and, in order to add videos, I upgraded my free account to a Collab, the lowest tier, that was informed as being able to add playable videos to my slides.

Then, I added my files with ease, all working just fine, closed the presentation and opened it up again later, only to find that I'm not able to edit my slides with Figma's design tools any more. Not only this presentation, but new ones I create too. The design tool option is greyed out, unable to toggle.

What is going on? I need to work on this presentation ASAP being able to work on it with all the functions I had with the Free version PLUS what I had just purchased. This whole situation is becoming really frustrating, since I already paid for a whole year.

Thanks in advance!