Manky carpet coming away from grips. Advice please.

[Saggingninja]

The rest of my carpet looks ok but just by the door to the bedroom the carpet is coming away from the grips and looks really manky.

I can't get rid of the carpet because I do a lot of voice work and boards would make the room sound too echoey so I'm stuck with carpet. Apart from replacing the carpet which I don't really want to do does anyone have any suggestions? I've included a photo of my glamorous-looking carpet.

Fit a wider threshold strip? That one looks quite narrow and the carpet edge has started to fray so you would struggle to fit it back under that one.

Wider carpet gripper and an adhesive spray (carpet fitter uses something before fitting grippers but not sure what).

Thank you,