I took several shots on a Panasonic Lumix GX80 on 4k, at 24fps and 50 shutter speed. Most of the shots I took on a tripod have this strange distortion that looks like a heatwave on them, which is absent from the handheld shots I took. I'll attach one example.
As you can see, the shot is static, so I'm ruling out the rolling shutter problem common to many high-speed videos. The tripod was very cheap at it was a bit windy when I took the shot, so I assumed it was a problem with the camera shaking imperceptibly and an auto-stabiliser. As you can see at the beginning and end of the video, the tripod heavily shakes when I simply press the record button.
That is called the "jello effect". When using a tripod the image stabilizer in camera should be turned off. That may help in your case but probably not. AFAIK, there is no software that can rescue "jello effect" clips. Some CMOS cameras are very prone to this while others are not. Lot´s of info about it on any search engine. 🙂