PNG problem in new update

[defaultvv7jdazjbw8z]

Hi, for years now I have been saving a version of my final images as a 16Bit PNG using 'save as' and this has worked fine.  However, after the latest update, now when I try this method the image loses a lot of the colour and vibrancy.  So if I try the 'Export' method for PNG it will only allow me to do it in 8 bit sRGB (even though it gives me a check box option for 8-bit so no idea what that actually does - more on that later), then the exported 8 bit PNG is fine, I can then reopen convert to 16 bit and it remains fine and vibrant.  
So why has this new update trashed the way I 'save as' 16Bit PNG ? 
Incidentally, if I check the '8bit' option box in the Export panel it gives me the same washed out colour image that 'save as' does.  🤷‍:male_sign:🤷‍:male_sign:🤷‍:male_sign:
Regards 

Russ 

[TheDigitalDog]

There is a bug with the sRGB check box unchecked. It saves off untagged RGB which is likely what you're seeing here. You'll need to use the Assign Profile command and likely assign the RGB Working Space you have setup to this untagged document.