I downloaded 5.3.0 and installed on my Joomla 4 test site. I used it both with an article and with RSEvents, my results are below.

Article: the Track button now appears below the article editor and successfully inserts the track reference but it does not display the track or the elevation profile. 

RSEvents: the Track button appears below the event editor but does not insert the track reference. So I manually inserted by copying from the above article. However the track and the elevation profile do both display correctly.