Hi there,
As any addin may re-arrange the ribbon buttons, it is difficult to tell which addin may change the position of the button, I think you can try below two ways:
First way:
1. In the expanded panel right click the "Grip Snap" button and choose "Move to Main Panel".
2. Close and re-start Inventor, and check if the button is just remained in the main panel.
Second way:
1. Right click ribbon and choose "Customize User Commands...".
2. In the Ribbon tab, choose "Assemble Tab" for left dropdown list and choose "Assembly | Assemble" for right dropdown list , and locate the Grip Snap, and click the >>(Add) button to add it to right column. You can check Large & Text check boxes for it.
3. Click Apply and dismiss the Customize dialog, and you can move the User Commands panel next to Position if you like.
4. Re-start Inventor and check if the button is still there.
Please let me if this helps.
If this solves the problem please click ACCEPT SOLUTION so other people can find it easily.
Rocky Zhang
Inventor API PD
Manufacturing Solutions
Autodesk, Inc.