I see that your
max_input_vars is now set to 5000. Have you tried the number 1 and 4 solution in the list I've given previously though?
Your memory is unknown and that might be the cause of the issue. Please contact your web host to increase the allocated memory to 512M or higher as I've listed previously.
Also, if you have browser extensions, please deactivate all of them and test if the issue persists.
If the issue persists, please give us FTP access also. You can ask this from your web host.