Given the 53cm tank height, make sure you’ve got High Output T5 (HOT5) and the best reflectors - you may find that some plants do better in your tank than others, eg, Rotala Vietnam H’ra seems to bolt less in lower light than does Rotala rotundifolia (which is likely the fastest growing Rotala so a good start up plant)
The H’ra is also slower growing, it may take a few weeks to establish, then you’ll see faster growth
Felipe Oliveira plays with water column fertilizers to slow his stem plant growth (he discusses this in his home tank video, also mentions a little in the recent AG workshop video) so you might look at this method
What is your H zosterfolia doing?