Hello, Naylor here.

I've had success with the stablisation in 26, but could you explain if it's the same clip you are trying again, or a new one? The Stablisation pass which  collects the data that is then applied to the properies effect will not be regenerated a second time you use render and play with differeing values - it's just the way that it is interpreted.

To preview the stablisation smoothly require you to have Playback Optimisation set to a sufficient level to see the effect of the properties.