Why is my Apple Watch Series 9 showing low heart rate alerts after the watchOS 11 update?

I have a Watch9 and recently updated to watchOS 11.0.1. Since then I have twice gotten warnings that my heart rate has been below 50 for ten minutes. Considering I have a pacemaker set at 60 bpm I doubt my watch is correct. I have has the watch since last December and have never gotten these message before. Has anyone else gotten these notices?

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