I think Reflection for HP is the same as Micro Focus Reflection which is the same as Attachmate Reflection... there have been a few takeovers in the terminal emulator space.
There is a knowledgebase article if you have not already seen it:
https://blueprism.knowledgeowl.com/help/how-to-configure-micro-focus-re…
From my experience things to watch out for are ensuring the hllapi settings in a terminal emulator are turned on, ensuring the hllapi/ellapi/winhilli/whateverhllapi dll is in the environment path. Ensure there is no other hllapi mainframe installed on the desktop that has a hllapi dll that can be picked up by mistake.