I suspect that 802.11v is doing what it should be and trying to balance the client load. The issue is that if you don't know how it does that it can have unintentional consequences.
Unfortunately, even if you turn off client balancing in dashboard it doesn't actually turn off 802.11v. Therefore the only way to stop this from happening is by having a good RF design with an understanding of the types of client's and how they choose to roam.
Normally when I see this it's that APs are turned up too loud and all the APs by entrances and exits have the majority of the client devices attached.
The issue is that 802.11v tries to force the clients to do things they don't want to do. Some clients will them blacklist those BSSIDs as they don't play nicely. Then you end up with wi-fi dead spots etc.
in short - either do some troubleshooting by running packet captures to see what’s happening (I’m willing to bet it’s 802.11v) and then do a redesign. Or just do a redesign.
Please feel free to hit that kudos button