Rocker26a
Adventurer
I could easily see Ranger developing their own particular spells that can be cast from stealth. Like Hunter's Mark.
Just not every spell. That's game breaking.
Anyone's free to disagree of course, but I don't think keeping it locked to just the Ranger spells (and those considered Ranger spells via subclasses) would be that big of a deal. It's a neat thing Rangers can do to keep up their stealth edge in close quarters/get an advantage against a more full fledged spellcaster, etc. but they can't pass that benefit on to other spell lists they multiclass into (unlike a Sorcerer's Metamagic or similar).
When a Ranger is hiding in the thicket, stalking some poachers moving through their forest, it should be fine that they can cast Jump to get up to the canopy without breaking stealth. But they wanna cast Shield of Faith from their Cleric multiclass when they're up there? Then they've gotta make a judgement call.
If you vehemently disagree/think that's too much, could make it a variant rule instead, similar to the Additional Spells from Tasha's. It's something I've got in my homebrew that I discussed in another thread a while ago, the idea that there's a core set of spells every Ranger ought to get without counting against their total. Somewhat inspired by that "all warlocks should just get eldritch blast for free" thing. Could use that sorta framework? "Rangers get these specific spells when they reach these levels, and when they cast them with a Ranger spell slot they require no components: Hunter's Mark, Pass Without Trace", etc. Maybe that's a workable compromise for a DM that doesn't want to open up the whole Ranger list?