Zwift newbie: troubleshooting a standing climb

Hi folks,
I’m a seasoned indoor cyclist (riding Kaiser) and outdoor cyclist who is new to smartbike and Zwift. I am already loving it, with the exception of standing climbs. The resistance just doesn’t feel steady throughout the stroke. I have tried dialing resistance up; that doesn’t appear to be the issue. Wondering if it is related to weight distribution and center of gravity bc I am a pear-shaped lady even when I’m all trained up and I’m hardly that at the moment due to some chronic health conditions that limited aerobic exercise over the last two years. I was just starting to get my mojo back when the pandemic shut down our gym and bike path, hence the investment in Zwift/Wahoo Kickr smartbike. Wondering if perhaps the Wattbike is better on this, as I’ve never had a problem during indoor classes on the Kaiser? I’m loving so much about it and would like to make sure I’ve gotten this final detail dailed in for the long haul. Thanks in advance for your feedback.