Since a few weeks I have problems with the drupal core update. I am on version 7.83 and as 7.84 was released I've tried to install it as usual, (clear everything beside the sides folder an some theme files, then ftp the new files on the server and update the database with update.php) but the database update allways shows the message "no pending updates" which should not appear according to the UPGRADE.txt file. So I thought the release of 7.84 is broken and decided to wait for the next release. Now we are at version 7.87 (7.86 is a security update) and I have the same problem with all of those versions. Now my website runs good with the files of version 7.87, but if I look at reports available updates it show that I am on drupal core version 7.83 and if I try to execute the update.php there is still the message "no pending updates". What can I do to fix this problem or do I have to reset my drupal instance?