Go through the following steps:

1. Check if you have this (or the hexed) addon and the other addon installed. If they aren't, you know what to do.
   
2. Check if this addon (or the hexed) are located at the bottom of your load order. To ensure they do, go to your GMod properties, click on the workshop tab, and search for this addon. Right-click on the addon, and click "Move to Bottom of Load-Order." By placing the addon at the bottom, this ensures that it will override the physics of the TF2 characters
   
3. Check your filesystem for any physics files (.phy). To get to your filesystem, go to your GMod properties, go to the Local Files tab, and click Browse Local Files. In the search bar of your operating system, search for "demo.phy" (you can also use the other mercenary names). If you find any, you need to delete them. These physics files in your local GMod directory take precedence over workshop addons. Hence, you need to delete them so that you see this addon's features

If you have gone through the above steps and find that it is still not working, then it is likely a bug with the addon itself! In that case, you can post a bug report, and I will assume that you have followed the above steps. Please go through these steps before you file a bug report, or it will be difficult for me to determine if it really is a bug or an issue with how this addon is installed

Please start a new discussion in here so we can discuss how to solve the problem. If it is related to the hexed addon, start a discussion there.