Is there a size limit to external hard drives that smart TV's can use?

Hi all,

I've been using a 2TB external hard drive to watch media on my Hitachi smart tv for the last 3 years with no issues. The 2 TB is almost full, so last night I tried using my 6TB hard drive and the TV wouldn't even recognize it. So I tried a 3TB hard drive and it wouldn't recognize that either.

All 3 were connected by usb and have their own power supply. All 3 are also formatted to NTFS.

I'm thinking about buying a new TV at the moment, but would like to know if there are issues with the size of hard drive TVs can recognize.

Thanks in advance.