prevent receiver components from interfering with output of modulator
Take a look at C2.

When just your scope is on it, all is good.  The scope is practically no load at all, and the high pass made of C2 and R4 has a cutoff of around 16MHz (below the 27 MHz being discussed in your other question.)

When you put your demodulator on there, you change that high pass filter.  I expect the impedance of your demodulator input is low enough to raise the cutoff to the point that nothing gets through.

Easily checked:

Move the scope connection to the other side of C2.  If you have your expected signal at the junction of C2 and R2, then you've found the problem.

In that case, use a larger C2 or put a largish resistor between C2 and L1.