compression leg sleeves / tight calves

I need opinions from people.  I have very tight calves, not like muscular, but like tight and restricted in stretching ability. I've been a runner for years and this tightness developed a few years ago.  Whenever I start running races (mainly half-marathons but also sprint tris ) my calves are so tight.  It's not cramping.  I've made sure I'm always well hydrated. I stretch. I try doing a light jog before the race starts.Nothing seems to help.

However, I notice this is mainly a problem when I run outside. On the days I've trained on a treadmill, it's normally not an issue.

I've done a few races with compression leg sleeves but I didn't necessarily feel a difference. Does anyone have recommendations on those sleeves? I'm willing to try a different brand. I used Zoot before.