Weird, Gooey baked goods

We have been using my All purpose flour mix for a long time now, maybe close to 2 years. It has always worked perfectly for us, until recently. I mixed up a batch and made muffins. They were weird. They had sort of a gooey, bouncy texture to them.
I was baffled to say the least. I shrugged it off, figuring I had measured the wrong amount or something. So I made cookies. Again, weird texture.
It (finally!) dawned on me that what was different was that I had run out of Xanthan gum and was using all Guar gum! I had always thought the two were interchangeable. For me, they aren't. It is possible that the guar gum would work ok alone but just in different amounts but I just don't have the patience to try. I really favor a mix of guar gum/xanthan gum in my baked goods. I always use 1/4 teaspoon of each per 1 cup of flour.
Needless to say, my pantry is again stocked with xanthan gum!