You are right. I see exactly the same. I thought you coudn't try "," as you didn't see it on the keyboard.
So entering a number with "." in any language mode causes the field to get highlighted red indicating invalid entry. Tapping "," is ignored such that 9,5 becomes 95.

I had expected SD Team to comment on this.

Even if there is a "," symbol on the keyboard, nothing happens when I press it.

If you don't see the "," symbol on your keypad, then that is related to the keyboard selected. I noticed the same when using the original Samsung keyboard (the popup keypad only shows numbers and "." for entering values in these fields). When I changed to SwiftKey keyboard, I could see the complete keyboard with all symbols, including "," "." etc.

Ok, then your problem is different from mine since I can *not* enter a decimal comma when a comma is required, but I *can* enter a decimal point.

The first thing I did was to check if this issue could be related to decimal point being "," or ".". I normally have my tablet configured in Norwegian language mode expecting "," as deciaml point. I then configured it to English language mode expecting "." as decimal point. In both language modes I checked with the original Samsung keyboard that comes with the tablet, and also with SwiftKey that I normally use. I even tried with a bluetooth keyboard. The exact same error in all combinations of language modes and keyboards.

So the field simply doesn't accept decimal point, even though the default value in the different fuel burn fields all are displayed with decimal point (which correctly uses "."/"," depending upon language). This is a hard error in the SD Android software.

The only workaround is to do all aircraft profile editing of the fuel burn fields on my Windows laptop.
This is an error that SD has to fix.
There is no reponse from SD yet, but I hope they have seen my report here.

I have basically the same problem, although the exact behaviour is very slightly different (maybe because of a different device or Android version).

I am running SD on an Android 4.3 tablet and on PC with Windows 7.
I try to create an aircraft profile. Part of that is to enter several fuel burn data. That works fine on the Windows PC.

But on my Android tablet I get an error message when trying to enter a decimal point, as the field is high lighted red when hitting enter. I have tried different on-screen keyboards. Doesn't work.

Here is what happens:
Tapping the fuel burn fields for Fuel, Climb, Descent, Power Settings ("Taxi/Takeoff", "Landing", etc) changes the selected field into editing mode and a keypad pops up. If I try to enter a decimal point and hit Next, then the field gets high lighted red and the entered value is ignored.

I haven't seen any thread on this issue on the forum, so is it only me having this problem? This is very frustrating, so I hope SD can fix this quickly.