Stephanie, you have my sympathy and my total understanding.  I've been there--including the block scheduling.  My reaction was retirement soon after what you're describing started happening (pre-COVID for me).  But hindsight is a wonderful thing.  Here's an idea:  When the comments come from YOU, it comes across as you, just you, complaining about what the administration believed, no matter what WE think of it, was a convenient solution to a problem. But sometimes we need to PROVE we're needed.  Enlist teachers you have collaborated with in the past.  Sit down and talk to them, and to teachers who have expressed an interest in collaborating, or with whom you would like to collaborate, and put together a slate of lessons you'd love to do --but cannot because of the study hall situation.  As a group, approach the administration and explain this (make sure you have the ideas fully fleshed out and realistic, dates, timelines, etc.).  It's sad in this day and age, but administrators STILL don't quite know what their librarians are or do or are supposed to do; they still think of us as bound to the library and in charge of what- or whom- ever happens to be within its walls.  For years I've said that librarians need to infiltrate administrator certification programs and conferences, to bring them into the 21st century.  But I digress.  The reply your administration would say to YOU, alone, might not be the same reply he/she/they would want the rest of the faculty supporting you to hear, or it could be worded in a more open way that would allow for some progress.  Ultimately, though, when I was in this situation, I thought about where my own priorities as a teacher librarian lay, what my value to the school was.  Was I a teacher first, or a study hall monitor first?  Needless to say, I was a teacher first.  So, if I was invited (or invited myself) to do a collaboration in a classroom (given that a library full of study hall kids was untenable for most groups), I let the administration know that I would be outside the confines of the library for that period/block, and it was up to them to find CERTAIN coverage (not the assigned teachers who never showed up).  The more it happened, the more they'd have to rethink the whole study hall situation.  Passive aggressive much, lol?  If I hadn't been that close to retirement, I'm not sure I would have risked it.  It  did not make for a comfortable relationship with the administration. 

Best of luck.

Cathy Andronik

Retired, Brien McMahon HS, Norwalk