I try to enable template hints in Stores -> Settings: Configuration -> Advanced -> Developer -> Debug
But if I make my changes and save, then it reloads and the settings are reseted to the values they had before the change.
I also tried it via CLI
php bin/magento dev:template-hints:enable Template hints enabled.
but if I reload the settings site, then it is still set to disabled there. There are no errors in the browser console.
I checked the table "core_config_data":
SELECT * FROM `core_config_data` WHERE path LIKE "%template%"
As you can see it is enabled.
But if I reload the frontend with parameter
?templatehints=magento e.g. http://entwicklung.fresh.m2/besteck.html?templatehints=magento then it does not show template hints. Of course I cleared the cache.
I am in developer mode, not production.
php bin/magento deploy:mode:show Current application mode: developer. (Note: Environment variables may override this value.)
I even updated to the latest version as of 2.3.5-p1