Welcome to HCM, and be assured that you've come to the right place to alleviate your worries.
"Is there something wrong with back again?" -- I don't think so, not AGAIN.
The line "appearence is not significantly changed compared to the prior MRI" sums up much of the story and is reason for relief.
At the same time, your spine is not "normal". In addition to wear & tear and aging, your spine had to bear the brunt of an operation. 'Epidural fibrosis', 'grade I anterolisthesis' etc point towards that 'brunt'. Above all, you have nails and screws holding your spine in place. So you'd have to go on adhering to the precautions and exercises your surgeon / physiotherapist may have advised you.
Other than that, the "L4-L5 disc bulge and facet hypertrophy" and "suggestion of moderate bilateral neural foraminal narrowing (at L4-L5)" are things that may need to be watched. However, the fact that "appearence is not significantly changed compared to the prior MRI" means that there isn't a lot to worry about L4-L5.
To sum up, unless your previous symptoms (pain, numbness
, weakness, etc) recur, all you have to do is follow the precautions and exercises you've been advised. No worries. No anxieties.
Wish you all the best.