The behaviour raised previously in this thread was MSFS 2024 specific and related to some specific WASM initialisation logic that isn't required in MSFS 2020 (that logic was also fixed in the v0.1.4 update, which added native MSFS 2024 support).
It's tricky to diagnose behaviours such as the one you are describing without knowing more information about the aircraft's state and the steps taken leading up to that behaviour occurring.
What I would recommend is firstly double-checking that the aircraft is set up correctly with the appropriate electrical power for that stage of flight (there is a tutorial flight from page 206 of the RJ Professional Operation Manual that should walk through the process of configuring the aircraft for flight: https://downloads.justflight.com/products/JFF003765/RJ_Professional_MSFS_Operations_Manual_MSFS2024.pdf).
If the A/T behaviour persists when following the steps in the tutorial flight, could I kindly ask you to raise a ticket with Just Flight Support at the following link: https://www.justflight.com/support
In the ticket, if you could include steps for how our support team can reproduce that behaviour, and ideally screenshots/videos showing the behaviour, then our support team will be in the best position to be able to offer assistance.
Mark - Just Flight