t → g (no) → Let’s try the opposite:
: Use an online “keyboard shift cipher decoder,” try left shift, then adjust obvious typos (e.g., m→y, n→b) manually until you get an English phrase. thmyl brnamj kalboard
t → r (if shift left, t becomes r? Actually QWERTY row: q w e r t y u i o p → t left is r, yes) h → g m → n (no, m left is n? m is between n and , so left is n? wait, n left is b – so this fails). t → g (no) → Let’s try the
(each letter shifted one key to the left on QWERTY): m is between n and , so left is n
Given the complexity, I’d say the intended phrase is likely or "the new brown keyboard" depending on a consistent shift pattern plus a couple of manual corrections.