You might see unexpected power values if the weight setting on your Stryd pod changes.
Weight affects how many metrics, such as power and your Run Stress Score are calculated.
Height affects how Leg Spring Stiffness is calculated.
Note that your weight and height are stored with the data for each run. This means that future changes because of change in weight do not affect historic data. At this time, PowerCenter does not allow changing the weight and height after your run has already been recorded.
In the current software, it is difficult to know the weight settings for each run in the past. This makes it difficult to compare performance between runs with different weight settings. For the large majority of users, it is recommended and best if you keep the weight setting on your Stryd pod constant.
If you really, really want to keep the weight setting on Stryd up-to-date, you can do so. While it is easiest to use Stryd if the weight setting on Stryd is constant, you can update it continuously.