We are also having the same issue with numerous Number fields not disabling. The last community posting with the same issue was from 4/2020. There was a work around suggested from the site below. However, it is not working.
We are also having the same issue with numerous Number fields not disabling. The last community posting with the same issue was from 4/2020. There was a work around suggested from the site below. However, it is not working.