Were the laws elite liberal before that? One thing that can come up when you have a majority of Liberal, but not Elite Liberal, justices, is that they don't like laws being all the way at L+. The supreme court behaviour is very basic - every judge just wants the law to match what their personal alignment is, with a bit of bias towards certain constitutional rights (a liberal bias on free speech, a conservative one on gun control, but these are ignored for C+ or L+ judges), so if the law change would push it closer to their alignment, they vote for change, otherwise they vote for status quo. The laws they vote on are random, but there will always be a few, and the more elite liberal laws you have the more likely that there will only be one direction for them to go. The only way to guarantee the supreme court won't push laws backwards is to have 5 L+ judges on the bench.
This is a pre-existing issue from the original game; some versions implement a special case where when the rest of the government is already elite liberal, they can propose a constitutional amendment that flushes the entire supreme court and replaces them all with L+ judges to speed up the endgame, but this isn't (currently) implemented in my version.