I added two dots to my Excel references and my slow workbook came back to life
https://www.makeuseof.com/trimrange-and-trim-references-in-excel/
- TRIMRANGE and Trim References
The dots that tell Excel to stop wasting time on empty cells - How A.:.A (or A:.A) fixes whole-column lag
Speed up whole-column formulas, LAMBDAs, and dynamic arrays