After the use of a External fuel tank engines won't detect the onboard fuel source.

[Dermeister]

I'm using real fuels, i'm not using Realism overhaul.But i'm using RSS

I don't know if it's a bug or if i'm doing anything wrong but i'm in the process of designing a space shuttle. I have In the external tank LOX and Liquid Hydrogen. I have a tank inside that tank comprised of an auto mixture of Areozine50 and NTO( which is what my OMS engines use).  I have onboard fuel tanks IN THE SHUTTLE to which I have deactivated for the duration of the launch so that I don't accidently use up my onboard fuel( stored for final circularization and orbital maneuvers ) It's also Areozine50 and NTO.

The problem is that when ever I go click on the onboard fuel tanks for the Areozine50 and NTO my OMS engines think it's out of fuel? I don't know what's happening but clearly I have fuel as you can see In the screenshot! Further testing on the runway recreates the issue I have in space after SEP, But I've noticed that if the on board fuel tanks are Activated before you stage the engines, then the engines fire just fine as shown here.

You can clearly see i'm using the onboard fuel. So it seems like if you have the fuel tanks turned of and you stage the engines and then later activate the fuel tanks the engines do not detect the newly activated fuel source.

Is this a bug? Incase it is a bug i'm leaving my log and mod list on the event that some of the moders who can fix this problem are reading this. If it's user error then I would appreciate help to find the solution to this  thank you.

 

Here is the craft file and Log.

Dropbox link https://www.dropbox.com/s/gceilhwnteg3opz/Fuel Flow issues Craft file And log.rar?dl=0

Let me know if this link doesn't work ill find another way to share the files.