I've seen several posts that are similar to my issue, but no perfect matches. I have a line feature layer that is symbolized using an Arcade code block. The symbology works in Pro and in Map Viewer, but when you open that same web map in Field Maps, all of the lines default to the "other" symbology instead of matching what's in the legend. Are there limitations on Arcade-driven symbology in Field Maps? If it matters, I'm on Field Maps version 25.1.0, build 1141.
Can you share the map with me so we can investigate? Feel free to DM me the details