No, I have not tried latest stable release 19.07.7 yet. But I agree: the problems with Luci, 5GHz-Channels, country selection and DFS seem to be correlated with open vs. closed source drivers for the Mediatek chipsets. As I occasionally found in another thread (2021, gl-inet Firmware 3.2, shorttest of snapshot version - #29 by luochongjun), luochongjun is already aware of the problems. The core question is: will the gl.inet-developers team be able to fix the issues at least with FW 4.x or will they not - assuming that MediaTek will not grant open access to their code …