I've using an Aklot banjo uke, and having trouble keeping it on my lap. It slides around a lot, and I'm finding myself hunched over to keep it still which is making my chords feel crunched and horrible and the whole instrument seem angled too far towards me. I've read about non-slip mats on the forum, but the aklot is open-backed, meaning there's little space to attach a mat. Suggestions are appreciated - I thought there might be a mat I could rest over my legs while playing? I did try using the strap, but it doesn't really help the problem.