I've stopped the chest to do the courses in the suggested order! :P
Not sure what I am doing wrong here, I decided to do a different shark from the one in your video (I thought it might test my skills a bit more) followed along with you and switched into object mode to make and place the teeth. I select the shark in object mode move over the sculpt mode but the tools ignore the model as if it wasn't the object selected. not sure what I am doing wrong. I cant seem to get sculpt mode working again. The screenshot probably wont help much in this case but still:
This has happened to me more times than I like to admit. Especially since I like to disable the mask overlay so I don't have to look at the darkened color of the mask.
I'm glad you figured it out though. Your shark is taking shape! I 100% affirm your decision to make a different shark from the art 👍