I’ve noticed that my tomato plants sometimes pause flowering for several days, and then resume. I’ve tried to tie it to weather conditions, but, while really hot weather is definitely a factor, often causing flower fall-off, sometimes the plants pause in moderate temps too, not flowering to begin with.
A shot of Bloom Booster or Super Phosphate usually encourages flowering if the weather is good, but, sometimes (less often?) plants I didn’t treat “come back” later with flowers, too. I’ve had tomato plants “resume” in early fall, other times even indeterminate types just quit entirely or even die for no apparent reason. (I suspect root diseases.)
I’ll keep bloom booster in mind for next year and beyond but I’m actually itching to pull every plant out of the tunnel, all six of them, and prep the soil like I should have done before a plant or seed ever went in there.