Problem with save only in products with 130+ combinations

[TouchTheSky]

Hi everyone,

I have Prestashop 1.7.6.4, PHP 7.1, MySQL 5.5.3.

Issue:

When I click save after few changes in product with 149 combinations, I get something like saving in infinity loop without any error. If I delete some of combinations and reduce it to 120 - 130 everything woks fine, after 2-3 seconds of save (after save button click) in right corner display notification "settings saved".

How it's look like:
After push save button, color change to gray (disabled) and the task look like processing but without the end (even after 30 minutes).

What I try:

1) Checked all formatting of text
2) Checked logs in Prestashop (Admin Panel > Advanced Parameters > Logs) - nothing about errors / bugs / any issue
3) Checked logs in VPS (txt files) - the same, just nothing 
4) Checked and changed few parameters in php.ini (best server settings)
// max_execution_time = 300 // max_input_time = 300 // max_input_vars = 10000

What can I more check or where to look for issue resolved?

Thanks in advance,
Martin

[Henrik41]

1. Restart your server or/and Nginx/Apache and/or php/php-fmp

2.  Update your prestashop to the latest version and upgrade your php to  7.3 (do a backup before!!!)

3. look at all the logs posssible.

[musicmaster]

Did you check for javascript errors?