The thing that you have to realize is that Texas polling is very inaccurate right now due to the pandemic.
A lot of people are not answering their phones because contact tracers keep calling everyone to try to tell them they may be infected with the virus. Nobody wants to hear that, and the people who want to hear that least of all are Republicans Trump supporters who believe that the virus is a hoax. Why waste your time talking to a contact tracer for a host virus?
So for this reason there are a lot fewer Trump supporters responding to polls at the moment than usual. So this poll is probably about 10 points too favorable for Biden, which means Trump is up by 5.
So Texas is safe Republican.
5 points up is lean, not safe.