UPDATE: I rewrote the post as I gathered more information.
I'm a MacBook Pro 2019 user, OS Sonoma 14.2.1.
I don't know where to retrive my Dropbox version, but it should be up to date as I always do updates when prompted.
I suspect my Dropbox cache is overloaded, and I guess it is not emptying itself for some reason. Unfortunately I have no way to verify this, as I can no longer find the cache folder. I tried with the usual Command+Shift+. in order to show hidden files, but I can't see any cache folder in the Dropbox folder, and I can't find it not even using the go-to-folder with the command ~/Dropbox/.dropbox.cache.
Also I can't find any longer the "limit my cache" option anywhere, so I can't test whether putting a limit can solve the problem.
Here are the reasons why I suspect a cache problem.
In the latest days Dropbox continuously reported me the "hard disk is almost full" warning. I have stored no huge files locally recently, but I have downloaded a lot of big files from the internet in the last 15 days or so. I guess a mean value of 10 GB per day. I stored them online only, and I know Dropbox cache should empty automatically after 3 days, so I don't expect these files to take more than a maximum of 30 GB of space (due to cache delay) on my local hard drive.
Then yesterday morning Dropbox stopped syncing as reported my hard disk was full. I deleted some huge file I had locally and some useless software I had installed in order to make some room and allow Dropbox to continue syncing my files. Then I checked the "Storage" option in System Preferences, which reports 218,2 GB used out of 250,69 total.
I have no such a huge amount of files locally, I'm sure I always keep local files under 100 GB. The Mac "Storage" statistics confirmed this: summing app everything they report from Applications to Documents to iOS backup files etc I get a total of 56.44 GB used. But the total used space reports 218,2 GB.
So I did a test: since yesterday I downloaded locally from Dropbox only some music albums I need in order to sync my iPhone with iTunes (my iTunes library is stored online only in Dropbox), I guess no more than 2-3 GB, so if the Dropbox cache was working well I expected today to find a total of 218,2 GB - 10 GB due to cache auto-emptying + 2-3 GB due to fresh downloads = 210,2-211,2 GB used. But it reports me 222,6 GB used. That is: it added the fresh downloads to the used space of the hard disk but it didn't delete anything from the cache.
Also, I had a similar problem a couple of times in the past, and I always solved it by emptying the Dropbox cache as described above, a thing that unfortunately I can no longer do as the cache folder doesn't show up.
A further problem, possibly related: I noticed that files in some folder tend to go online-only automatically, a thing they never did before. I have no clue about the criteria with which Dropbox chooses which file to put online-only this way, but I guess it's happening mainly in those folders which I otherwise periodically set manually to online-only in order to keep my hard disk ordered. Indeed in many other folders which I always kept available offline none of this seems to be happening.
So all in all I guess something is not working properly with the cache. Of course I can't be sure of this, but the point is that it seems I have no longer any means to verify this.
So could you help me to understand what's going on? And could you help me in order to understand how can I check the volume of the Dropbox cache?
Thanks a lot,
Vanni