S
Honestly, I don't know anything about coding, but from what I can find in the menu of the 0x52_urm mod I got installed I meet all those requirements.
But I think i figured out the problem. I think any sexual encounter with any of those 3 girls that you have, blowjob, sex, threesome, etc counts towards the requirement for the band harem of "have sex with 'girl' within the last 7 days". I think that condition somehow interferes with the battle of the bands trigger. for example, if you end up having the Kleio studio bj event trigger the wednesday before, then the battle of the bands button won't appear on friday, it will just be the normal practice button instead. So the solution is just keep going to the studio and practicing until all the studio sex events that are available to you have triggered. wait a week or more ,staying away from intimate acts with Kleio, Anna and Sasha, then on that friday you should have the battle of the bands button at the studio instead of the practice button.
That is what worked for me. I guess I should note that besides having the )x52_urm mod installed I also have the time mod installed which let me skip by the time faster.