I had the same issue at first (with Radioddity DG20 and Midland Hand Units) and discovered that Midland and Radioddity CTCSS charts are not exaclty the same, i.e. CTCSS 10 on Midland is not the same freq as CTCSS 10 on the Radioddity. But when I set them to same freq everything works fine (CTCSS 12 on DG-20 correlateds to CTCSS 10 on Midland.)