I tried unsuccessfully for several weeks to play home movies from USB on my late 2016 Bravia 55” smart (?)/Android TV. The same USB drive worked perfectly on a small Samsung in a spare bedroom. My USB devices were formatted as FAT32. Movie files were all less than 2Gb and were in formats listed by Sony as acceptable (mostly mp4).
I took my USB device to the retailer where I bought the TV (PC World, Milton Keynes, UK). They could not get my USB device to work with a single Sony TV in their store. Not one. They then tested the same USB device with Samsung and LG TVs which worked perfectly. The store’s Sony “expert” could not offer any advice other than resetting my TV to factory specs; this was meaningless as the Sony TVs in the store had the same problem. I called PC World “help” who, after I had waited for ages, claimed never to have heard of this problem and offered no solution or useful ideas.

I phoned Sony help who said USB devices must be formatted as ExFat.  That was it.  No other comment or help.
I created a new 16Gb USB “stick” formatted as ExFat. That worked!!!!! I then reformated a 2Tb external drive as ExFat. That did not work.  I reformated the 2Tb drive again using the reformat facility in the TV’s settings menu, which created a FAT32 drive, not ExFat as advised by the Sony Help line.  Anyway, after reformatting through the television the external drive worked, but the maximum file size it will accept is around 2Gb, not 4Gb as shown in this Sony video guide. I will next try a 1Tb external drive formatted as ExFat.
The picture and sound quality (through Sony sound bar) are superb, but the USB experience and lack of support has left me seriously underwhelmed by Sony.  A great deal of time-consuming messing around has been required to get my Sony to read USBs. It is pretty frustrating when other TV brands work immediately, and quite frankly unacceptable for a top brand like Sony.  The lack of help is also quite appalling, and the available manuals and YouTube videos appear to be incorrect with respect to drive and media format and size.

Can any Sony experts or fellow Bravia Android users comment or offer any advice on a simple way to play media from USB, and how to overcome file size limitations???????