Even if (after clicking the SAVE CONFIG button) the page refreshes and shows the text "You saved the configuration." the configuration still shows the old settings before the update.
I am experiencing this problem in the Stores > Configuration > Sales > Payment Methods section.
My magento version is the 2.3.0.
Is there any suggested way to debug this issue?
UPDATE: Actually is not showing changes after saving even in other sections (such as in Content > Configuration ). I tried to do an apache restart, cache clean/flush and a reindex and now some of the changes that I made seems to have been written in the db (since after these operations the updated values were showing in the admin page). Still I am not understanding why Magento is not able to show the changes that are saved in the db. Is the admin configuration page caching old values?