Yes, bug 1809764 should be the regressor since it fixed float elements in the multi-column layout, and the call stack in comment 0 contains functions handling float elements.
Bug 1833523 Comment 4 Edit History
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~~Yes, bug 1809764 should be the regressor since it fixed float elements in the multi-column layout, and the call stack in comment 0 contains functions handling float elements.~~ Yes, bug 1809764 is likely to be the regressor since it changes multi-column layout.