Is there a solar cover that is less likely to blow off the pool?

[matt4x4]

Same here on all counts!
Mine's a good quality mid grade cover.
Do you have steps with handrails and posts? If so, try adding some clips to lock it around the posts of the handrails, this may stop the movewment.

[cnk]

Unfortunately no handrails or posts.

[matt4x4]

You could try clipping stainless steel washers onto the perimeter of the liner every few feet as extra weight to keep it down - feherguard makes really nice clips that could pinch a washer onto it perfectly