I have no trouble placing my Camera Raw cache where I want to put it. Perhaps deleting your Preferences file would help with that problem.
Yes, if you embed fast-load data in your DNGs, LR will use that instead of the CR Cache.
Before I post here I reset Lightroom preferences and reinstal Lightroom. Nothing change.
I think that is ACR problem itself:PS CS6 / Bridge / ACR 8.5 - Camera RAW Cache settings reset non-stop
Problem occurs when I update Lightroom and ACR (5.5 and 8.5). Earlier everything works fine.
I try downgrade Lightroom to version 5.4 and in this version the same problem occurs. Maybe I should try downgrade ACR to 8.4 but I don't know how to do this.
Problem is solved!
I delete folder "C:\Users\USERNAME\AppData\Roaming\Adobe\CameraRaw\". Then I start Lightroom and I pick my own folder in Camera Raw Cache Settings, set 20GB size and click OK. Now everything works fine. Bridge and PS also fine.