I can't delete a synced device nor leave the sync chain

Hi everyone, I can’t delete a previously synced device, I keep clicking delete device but it’s not working, the same is happening when I try to leave the sync chain on pc. This isn’t happening on my phone. I’ve tried unninstalling and installing again but it didn’t work.

If this has happen to some of you and you’ve solved the problem i would appreciate your help/advice.

Thanks.