[ISSUE] No map received warning in RVIZ2 when following navigation example

[PVBrodersen]

Hi,

I am currently testing the nav2 stack on a physical TB3, and have gotten everything up and running till the point where I want to load my map into RVIZ2 -- follow this example. However, when I try to launch everything, I am met with the following prompt in RVIZ2.

As seen, the occupancy grid generated from the previous SLAM example (ensured that everything was called/saved correctly) is not shown in RVIZ2, and it promptly says that no map is received. Hereafter, I checked the TF2 view frames graph, as the logs from my terminal complained about a missing transform -- prompt:

Resulting in this TF2 frame graph:
frames_2024-05-03_13.36.35.pdf

I am a bit unsure how to proceed, and any help would be greatly appreciated :)