Hello Ruby... No idea about why Texas wouldnt honor MN Permit... My best guess is that Texas is a concealed-only carry state and MN is an open carry state... I do hope others would chime in about this... I do know that Minnesota doesnt accept many states' permit just because their requirements of purchasing permits is below Minnesota's standards... For example, Minnesota doesnt honor North Dakota, Montana, and Iowa permit because as far as I know, you are able to just walk in and apply for permit to carry in Montana and North Dakota without meeting any requirements (providing that you pass the background check) and just on-line course and test which consists of approximately 20 questions for Iowa...
I have a son who lives in Austin, Texas with his mom during the school months so being able to carry in Texas was a priority for me... I went for a class that covered Utah and Florida permit requirements along with Minnesota, seeing how non-resident permits from both states is honored by Texas...