Can you use Servo Stabilizer before a UPS?

I have a Inverex UPS (single battery, 1000VA Pure Sine). I want to place a Servo Stabilizer before the UPS to get constant voltage. However when I tried the UPS charged fine but when the Power went off the Servo stabilizer went crazy and I could see that its moving around a LOT. Checking the voltage it was clear that the input to UPS somehow still was showing a voltage (maybe the servo stabilizer neutral is somehow connected to power through a board inside?)

I tried two different stabilzers and both behaved the same so its not a UPS issue but maybe design of a servo stabilizer makes it incompatible to use with UPS wiring.

I am thining of connecting the neutral on the UPS output side to house neutral. Any comments? Ideas?

The UPS neutral and chassis/earth terminals should be connected to home neutral and earth connections respectively. Please verify twice that you are making correct connections before actually connecting the wires.

your connection / wiring is the issue. stabilzers always should be placed before ups.. there is no design problem.

servo or any stabilizer is best when placed before a ups. thus ups performs optimally and all appliances get fluctuation free proper voltage all time.