Anecdotally, I think there is some connection with the Navigraph data. I had the all-blank issue repeatedly, and the start on runway/change variant trick did not work. This was with the Navigraph data update installed. I uninstalled and reinstalled the RJ, and forgot to update the data again… and this time it worked.
I quit out and updated the Navigraph data on the new install – and, this time, I removed the Navigraph data from the 2020 installation in Navigraph Hub – and tried again to see if it still worked. It didn’t, but the start on runway/change variant trick DID work this time, and I was able to complete the flight normally. (Well, except for botching the RNAV approach entirely, but that’s a different story…)
I have not gone back to see if the “fix” has persisted. Wil update this when I find that out. But it does seem like the Navigraph data is playing some role somehow, at least to me, possibly involving having both 2020 and 2024 data updated in Navigraph Hub at the same time.