You should certainly follow KarrieRee's advise on lights. Always heat and UVB check again. Nothing else matters if that isn't on point.
On the probiotic topic, of course you should do your own research, but what I found for bearded dragons is that only Lactobacillus acidophilus has been shown to have a positive relationship with a bearded dragon gut biome. Most pro-biotics do include L. acidophilus. I used powder Bene-Bac Plus for Birds & Reptiles sprinkled on my dragon's salad. She was having runny poo. No parasites. I also changed her lights First to make sure the UVB tube was fresh and her hot spot was indeed hot using a few different thermometers to verify. It did seem to help her poos form, but then she went to brumate so I only had a month of consistant Bene-Bac with formed poo results.