Beto actually outperformed Biden in the RGV and Austin and nearly matched Biden in the Houston area (trailing Biden's margin by about 1% in most counties there). However, he lost massive ground compared to Biden in the entire DFW area (losing Tarrant and it's not even close, Abbott up by double digits in Collin and Denton) and in the rurals. This is basically the opposite of what we were expecting!
Well it’s not really surprising given Trump greatly underperformed generic R in DFW , greatly overperformed in RGV and Houston Area was a slight underperformance(at least in 2020, as it was a great underperformance in 16).