Thank you for posting, I have been testing on your Installation and found out that you have successfully set the value of max_input_vars to 10000
If you’re still facing the blocks disappearing problem then you would have to optimize the blocks usage, I can help with this if you would like.
If you have got a design (in PSD or any other format) I would gladly set it up for you using the page builder optimizing the use of the blocks, making the page faster as well as saving safely.
Examples for that would be adding less columns, to add them only when needed.
using Margin-bottoms instead of empty dividers
Using Team Member Title and Position attribute rather than adding them in separate blocks
I apologize for the inconvenience this is causing and will do my best to assist.