Anyone seeing issues with Excel 2016, OneDrive and FSLogix. Unable to open documents. EOL etc.

Office 2016 is end of life, so Microsoft are probably not testing FSLogix against it.

THIS, but Enterprise cusomers still using and get stuck in MS/CTX support loop until they get to L3, sorry not support lol

I feel your pain. We are having to push customers to 365 Apps, but they are not supported on Windows Server 2016/2019. So we are forced into server upgrades ahead of expected time as well.