You're welcome
I think I probably know what is the issue causing this after troubleshoot on your site, it seems like 2 plugin conflict with Metaman.
1. System - jQuery Easy
-> This causing can't store the correct data in database.
To solve this : I did try switch this plugin jQuery version from 1.8 to 3.x , it will store correctly when you submit the meta data from Metaman. (To test this, you have to disable this plugin "System - JFBCSystem")
2. System - JFBCSystem
-> This plugin have 1 ability to override the meta data on the page, mean when you open Metaman form, it will directly show the meta data even you already set.
Regarding this plugin, I still finding the solution for this, is it possible send us with your Jfbconnect latest installer to me so I can troubleshoot on my locally since I already found out what causing this issue on your site.
This is my email address : arlex.wong@stackideas.com