I don't think the chain was recently replaced. At least to my knowledge. This bike was bought brand new from a LBS on saturday.

TBH, I felt this while doing a test ride in the parking lot as well but I chalked it up to maybe it needing in a break in period but even at the slightest incline, gears 3, 4, 5 seem to be having issues.

No matter how much pressure i put into first gear, it have the sensation Im describing. This "slipping" feeling.

My stroke is pretty uniform or I should I say i try to keep it as uniform as possible.

I'll try to record a sound clip or something. Hopefully I don't fall while holding the phone and peddling.