Indeed a reaction to probiotics is likely to show you still have leaky gut issues.
I fdoubt the L-gluatmine feedsit. I have taked glucosamine for years to help with my joint pain, likwise is is an amino acid,yest it tastes a bit sweet.
For hives I would be inclined to suggest that your liver is the problem. It is definitely due to Lymphs issues. The liver cleanse the blod and then eventually the lymphs.
I would also suggest co-enzyme Q-10 supplements. To help with cellular detox.
Another way to help with leaky gut is to make your guts' lumen more alcaline. I use 1 teaspoon of baking soday in my psylllium to do so. As well as a bit of soda in my drinking water.