Non-slip running arm case for iPhone X???

Love running with my iPhone X.

However, the three arm band cases that I have tried so far to hold it end up slipping down my arm towards my elbow after running for a while, no matter how tight I ratchet the strap.

Any suggestions for specific cases that will "stay put" in the middle of one's upper arm, even when wearing slippery cold weather gear, would be most appreciated.

Thanks!