I have a Craft 3 installation where the plugins are not updating via the Control Panel. The process runs smoothly with no error messages showing up, and I get the All Done tick. The composer.json files are updated, and there is a change in files in the relevant /vendor folder, but the Control Panel the plugin version stays on what it was before, and it still shows up in the list to be updated.
This behaviour is pretty consistent. I can however install new plugins with no problem, it is just the updating that seems to be failing.
I assume it is not a folder permissions problem because of the new files added by the process.
Unfortunately I do not have command line access so I can't run composer. Which is suspect is the possible cause of the problem as I had to move all the files the old fashioned way from a local dev server.
I have two installations on the same server along side each other, and it is only a problem in one of them. They are otherwise set up similarly. So I am not thinking it is the server environment in general, but something specific to the installation, and that things have gone wrong with the way I move files around.
I'm thinking of copying everything down to my local machine and running composer again to see if it fixes this. The problem has only shown after upgrade to 3.2.x (the other site is fine on 3.2.x).