I will try to describe what happend as precise as I can remember :

-1 - I drove to a barel I found earlier.
0 - I opened the lid and emptied the content to my inventory, then I closed the lid, took the barel in my hands and droped it into the car (by drag & dropping it into car's inventory). After that, I drove back to my camp (5/10mins of driving).
1 - I took the green barel off of my car (an offroad) by drag & dropping it into my hands slot.
2 - I droped the closed barel on the ground (by drag & dropping into vicinity or by clicking the "drop on the ground" option, can't remember :/).
3 - Then I realised I couldn't interact with the barel - Right clicking on it showed no options but "Receiving".

From what I can understand, the server didnt register that I droped the barel on the ground because I could pass through it (I had no server-side collisions with the barel)

4 - I relogged to see if it'd fix the problem. After relogging, the barel was back in my hand slot but this time it had the lid opened (even though I hadn't opened the lid, from what I recall).
5 - I was then able to put items in the barel while being in my hands as it had its lid opened (Although it shouldn't be possible to hold an open barel).
6 - I tried to throw the barel on the ground as I was not able to drop it.
7 - After relogging once again, the barel was still in my hands and I found no ways to get rid of this situation.

Please ask for further informations

Keep up the good work! ;)
Cheers