OneDrive Storage Actual Limit

I have recently come across a weird issue. I am from India and I have a OneDrive storage paid subscription for 50GB data which is running since last 2 years without any issues. 2 days back My OneDrive stopped syncing, uploading and saving the files. A red cross was also appearing over the OneDrive icon. Every time I tried saving or uploading file, it was saying storage is full. But When I checked the storage status -it showed 29.7GB (59%) used and about 21GB (41%) is free. How is it possible? Initially I thought its an issue related to my OneDrive application in the Laptop. I unlinked the OneDrive, reset it, Uninstalled and re-installed it. But still the same. I tried uploading file from my android phone OneDrive- again its the same result. I tried through Web Browser -its the same message- storage full, but still showing 41% free. Then I logged a ticket with Microsoft support team. They checked it but could not resolve it. They escalated the case to the OneDrive team- but I am yet to get a call or any support from them. I waited for 2 days, still no call from OneDrive. But since all my working files are saved in cloud only, I was unable to work on files and time was running out. So today I logged in and did a tweak. I deleted few unnecessary files from my storage and almost freed up about 5GB storage space. So now the total used space gone down to 24.5GB. And guess what- the OneDrive started working absolutely fine. Now the question is- then what is the actual storage limit? Is it actually maximum 30GB in a 50GB plan? Or else what could be the reason for this unknown issue? I am still waiting for a support from the Microsoft team, but anyone here can possibly throw some light on this? Thanks.