I can reproduce in old Nightly versions as well. In sufficiently old builds (2020-05-13 and before), the icons are solid white (still broken-looking but a bit less bizarre). From mozregression, it looks like the solid-white-to-graphical-corruption change was from bug 1621433, and was generally an intentional change.
Bug 1827279 Comment 3 Edit History
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I can reproduce in old Nightly versions as well. In sufficiently old builds (2020-05-13 and before), the icons are solid white (still broken-looking but a bit less bizarre). From mozregression, it looks like the solid-white-to-graphical-corruption change was from bug 1621433, and was generally an intentional change (to foil attempts at canvas-based fingerprinting, not specifically to break Google Maps).