AD8232 R-wave chopped off

My AD8232 output has a chopped off R-wave (see image). This is the case for both Arduino as ADC and a Labjack U3 ADC. I tried to cut the output voltage in half (second graph in image) without luck. This also happens regardless of electrode placements. This leads me to think the chopping occurs in the AD8232, but what can explain this behavior? Is there some analog filter acting up?

Thanks in advance.

It would be something inside the AD8232 that’s causing it but I don’t know what it could be. Can you send a photo of the top and bottom of your board and a photo showing how you have things hooked up?