Q.Why Is My Tomato Plant Not Producing Blossoms?
I purchased a seedling Bush Goliath 3 weeks ago and transplanted it into a LARGE pot. It had one little tomato about the size of the end of my thumb on it when purchased. That tomato is now the size of a softball and the plant has tripled in size. There is no sign of any new blossoms. I also purchased a Red Beefsteak at the same time and planted in a different large pot. It is also doing well and has over 40 blossoms. Will the Bush Goliath ever get any more blossoms, hence, tomatoes?

Certified GKH Gardening Expert
My research showed a couple of possibilities for not flowering. Not enough light or too much nitrogen fertilizer. The puzzling thing is you probably are treating all the plants the same and they are flowering. Temperature can also affect flowering, but again, your others are flowering. I'm attaching some growing information here. If you don't see anything that pertains to your situation, I would replace the tomato plant.
https://extension.arizona.edu/growing-tomatoes
https://extension.arizona.edu/tomato-challenges
https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-temp-for-tomatoes.htm