Before you do any adjustments, get permission from your prosthetist. Also, after making the adjustment, tighten it up, walk a little, stop, and re-tighten . Patience is needed as your work on your prosthesis. This could be due to residual limb shrinkage or due to one dimension in the socket being wrong. Add socks if you have a silicone sleeve socket, or otherwise, go back to the prosthetist for some changes to the socket or a new socket 2 socket Socket feels like it is just barely hanging on.
Socket is too tight.
This could be due to muscle expansion. You need to reduce the number of socks, or the socket needs to be made bigger, or one dimension of the socket is off. A likely cause will be the area of the socket on the inner side near the pelvic bone. If the socket is too tight, the inner side of the pelvic bone might land on the edge of the socket. Socket shape may not be correct.