I always had the same question, but never got around to searching for the answer. Today's the day. https://www.google.com/search?client=firefox-b-1-d&hs=q5SU&sca_esv=9e0db00a775d1246&udm=14&fbs=ADc_l-aN0CWEZBOHjofHoaMMDiKpmAsnXCN5UBx17opt8eaTX5MJRoosnbembaWTjeNSquLeqRCxXBRGAkdJJ_SEV_4VZIQOaNPzfEm0o8TAIGA3dgI3f-MteWchEVNW4zC-tefNBs4jDRpFpqk4-rYVry17OJlfjEMXkf7MzLTN5j__R4X4kIW5WqXLG8UcDFvltmx_V7r9d0G1_QSrkW7XSmJyb1NC1Q&q=how+can+i+switch+between+firefox+windows+on+a+mac%3F&sa=X&ved=2ahUKEwjv3-PFrf-RAxUUFFkFHSkoJ64Qs6gLegQIZhAB&biw=1987&bih=1385&dpr=1&aic=0

Tried em. Command + tilde has never worked for me.

I'm sure someone out there is a mac user and will chime in. It is painful switching windows on mac. ;-))