BMW, QVC, etc… are initialisms not acronyms.

The answers you want are very specific. For example I recognised that they were symbols for chemical elements, but that they were also non-metals? Without Victoria Coren Mitchell asking you to be more specific it's hard to know how specific you need to be.

I also put just known my initials and didn't get it. But that's me probably.

I was surprised you have a Union Flag but use the US spelling of Sulphur!

Very poor grid

Didn't accept “gas” for the first line, despite it being more specific than the expected answer.

Also, it seems a bit silly that you can complete the grid just by picking all the 1-letter answers, then the 2-letter answers, before having to actually think.

You have put DNKY instead of DKNY