Forge version: 14.23.4.2705
Twilight Forest version: 3.7.424

Steps to reproduce:

1. Create a new world
2. Go to Twilight
3. Spawn in a blank magic map
4. Open the blank magic map
5. See no player marker

What I expected to happen:
The player marker should appear showing the direction the player is facing and where they are on the map

What happened instead:
The player marker is missing

Agh.. that was it. Didn't see blank one in JEI until you pointed that out. Thanks

Unable to reproduce on my end. Are there any mods installed that affect map rendering?

Fresh instance, fresh world, just went to the Twilight Dimension and cheated in a map:

Mods Installed:

Forge: 14.23.4.207
JEI: 4.9.2.196
Twilight Forest: 3.7.424

To be clear, how did you cheat in the map - did you spawn in an empty map, or a filled one?

You'd need to open the map to get added to it, I believe, but I don't think vanilla maps are different in that regard.