Weight is an important factor when calculating your power. If you something does not look right with your power measurements, likely the weight is not set right. The information in PowerCenter and on the Stryd app on your phone are not necessarily the actual weight set on the device. For example, this can happen when you borrow a Stryd from a fellow runner and forget to update height and weight.
There is currently no easy way to get the weight from the device. However, there are some developer tools available to get this information. For iOS, there is LightBlue Explorer and for Android there is nRF Connect. Both apps allow you to scan for Bluetooth devices. If you Stryd is operational, it will show up in the list.
After installing the app, scan for Stryd (Scroll down if you are using nRF Connect on Android).
If you are using LightBlue Explorer and have an iPhone, connect with Stryd and click the "Show" link next to ADVERTISEMENT DATA. It will show you data as below. Note the 13th and 14th digit of Manufacturer Data (48 in this case). This is the weight in HEX. Convert to decimal, which will give you your weight in kg (72 kg in this example).
If you are using nRF Connect on an Android phone, do not connect with Stryd but rather click on Stryd to expand the view (see below). Note the 9th and 10th digit of Specific data (58 in this case). This is the weight in HEX. Convert in decimal, which is weight in kg (88 kg in this example).
If you need additional help, contact firstname.lastname@example.org.