Iphone favors mobile data over wifi

New issue with my iphone XR... man they must be pushing those 12s hard! Anyways, my phone lately has been refusing to use wifi over mobile data, forcing me to put it in airplane mode (just because it's easy). I only have one bar of mobile data at my house which is how I've figured it out, any time the signal grows week I dont have any internet because it refuses to use the wifi. I can jump on my laptop without an issue. it is so irritating.