Key takeaway: If you just bought a Sony A7RV or A7IV and your LM-EA9 is from 2020, you are likely missing critical compatibility.
Unless your current setup is 100% perfect and you never plan to buy a new Sony camera or Leica lens, you should update your techart lm-ea9 firmware to the latest stable release (V4.0 as of now). techart lm-ea9 firmware