Product will not show on liv website

[panne003]

Hello,

When i update a product in my virtuemart 3.0.16 webshop (and joomla 3.9.12) and i save it. De product will not show in de the live shop. I use on the server php 7.3.9. I discover when i set the php version on 5.6.40 and change the product and save it and set the server after the change to php 7.3.9. Then it wil be show on the live site.
All what i want is use the latest php version because soon i will be update virtuemart to the latest version (when all the plugins are ready for virtuemart 3.6.3.
When php 5.6.40 is on then the field customergroup "select all" is available. When php 7.3.9 is on then the field customergroup  the select all is gone. I think there is my problem, but i don't no how to fix it. (see the printscreens).

[StefanSTS]

You need at least VirtueMart 3.4.2 to run PHP 7.3.

So first update then switch your PHP version.