Disabling works for me on j3.8.1+S3.14.1

Are you sure? I have the same system configuration. For backend (Admin tab) it always reverts to email validation again.

Talking strictly about validation I'm sure

But if I enter something like asdasdsd in the form it does not save, seems it is checked again on the saving time by joomla

I have definitely J3.8.1 with S3.14.1

http://recordit.co/pIIlpeHj9D

If this is on the hosted site it is possible that some protection like mod security is blocking request in background, check what responses you get to ajax requests when you change validation.

Is it this overview?

1. ffp[user_email][markup]:
2. ffp[user_email][markup_class]:
3. ffp[user_email][conditional]:
4. ffp[user_email][conditional_options]:
5. ffp[user_email][computation]:
6. ffp[user_email][computation_options]:
7. ffp[user_email][access]: 1
8. ffp[user_email][restriction]:
9. ffp[user_email][restriction_options]:
10. ffp[user_email][required]: required
11. ffp[user_email][required_alert]:
12. ffp[user_email][validation]:
13. ffp[user_email][validation_options]: {"alert":""}
14. ffp[user_email][stage]: 0
15. ffp[user_email][live]:
16. ffp[user_email][live_value]:
17. ffp[user_email][live_options]:
18. ffp[user_email][label]: Email
19. ffp[user_email][label2]: Email
20. ffp[user_email][variation]:
21. ffp[user_email][variation_override]: 

Hi,

what you posted is a request, usually there is another subtab that shows you response from server (can be just status like 301 or json, xml etc..)