Totally missed this…
14790: Fix the one-based addressing setting
Converted the One-Based Addressing setting in Modbus devices to Zero-Based Addressing.
In the Nightly Changelogs
After I updated to the 8.0.6 Nightly (from 10/28) and I couldn’t write to any PLC tags. Recieved “invalid address” error.
When I reverted back to 8.0.5 I still had the same issue! Then I realized that the zero-based addressing check mark in the devices advanced setting had cleared.
While using 8.0.5 I checked the setting and everything worked.
Updated to the 8.0.6 Nightly and unchecked the setting and everything is working.
Wanted to share in case someone else is scratching their head.