I upgraded my Mac to Catalina, bought Fusion 12 PRO and created a virtual MACOS Mojave machine by retrieving all apps from Time Machine.
Now I realize that the function keys don't respond the same to the real machine, but in the virtual machine preferences ---> keyboard there is no choice I used over the real one regarding function keys.
This is the option in the Catalina real machine:
while in the virtual machine this choice is not there
I waited a long time, with a lot of patience, for my problem to be solved.
You have written to me several times "This is to keep you informed that we are actively working on the support request and will keep you updated" but it is now more than 3 months that I cannot use your product due to this serious lack of functionality.
I am sorry and embittered, I do not know if in the future I will still use your products, but if I am not satisfied you will no longer have me as your customer but as a sure detractor of your assistance.
First a couple of things..
Your mention of support request, suggests that you also have a support request for this open.
The forum here is for VMware Fusion users helping out other users, this is not an official support channel.
Thirdly, I don't work for VMware, but am "one of those users helping out".
With all that out of the way, I'm not 100% sure that I understand what your problem is, but I am guessing that you have a MacBook Pro with a Touchbar and you need to use function keys in your VM(s).
This is a configuration on the apple side of things. So in your macOS host operating system, you can configure that when an application is active, it should ALWAYS show function keys.
In the menu (of your host, Fusion does not even need to be running), apple -> preferences -> Keyboard, select the tab page "Shortcuts"
In the left hand side you have an option "Function Keys", use the "+" button to add VMware Fusion to the list.
Hope this helps,