https://patriabook.com/post/681032_windows-leaking-at-the-bottom-corner-of-the-frame-or-where-the-glass-meets-the-s.html

Windows leaking at the bottom corner of the frame or where the glass meets the sill typically indicates cracked caulking or glazing. Caught early, this issue can usually be repaired by stripping the old sealant and replacing it.