No Sound/Signal from Looper X

When I try to use the looper and FX loop in the same path, I either get no volume or no signal. If I put the looper before the FX Loop, I can record a loop, but there’s no sound coming from my FX Loop (my amp). If I put the Looper after the FX loop, I get my sound back, but the Looper doesn’t pick up a signal. What gives?