A principle is something you follow blindly, something that doesn't need a judgement call, and these do exist. Stuff like "Don't use goto", "Structure your code well", "No compiler warnings" and so on.
Something like the Liskov substitution principle.
That's why modern guidelines and styleguides separate stuff into "must" and "should", and a principle is always a must.
Not sure if SOLID was meant as "should". At least when I was at university it certainly was taught as "must" and a lot of coworkers of mine also treated it as "must".
But anyway, it's super old stuff. SOLID was created in 2000. That's a quarter century ago and a ton has changed since.
Even Clean Code will be 17 years old this year. It's time to revisit all that, and most of it is just not nearly as good as it looks.