First of all, example assertions are swapped

assert texas_referee("2s,3s,4s,5s,2d,7h") == "7h,5s,4s,2d,2s", "Two Pairs"
assert texas_referee("2s,3s,4s,7s,2d,7h") == "7h,7s,4s,2d,2s", "One Pair"

Those lines should be:

assert texas_referee("2s,3s,4s,7s,2d,7h") == "**7h,7s,4s,2d,2s**", "Two Pairs"
assert texas_referee("2s,3s,4s,5s,2d,7h") == "**7h,5s,4s,2d,2s**", "One Pair"

Then a wrong test added today (my solution published yesterday failed on this test).

texas_referee("2s,3s,4s,5s,7s,2d,7h")
Your result: "7s,5s,4s,3s,2s"
Right result: "7h,7s,5s,2d,2s"

Obviously wrong since there is a flush at very beginning.