AWS did reply to my support ticket after reaching out to the internal EBS team:
Your volume vol-0962cfcd0b28acb95 experienced higher than normal latency while modifying. This issue only impacts volumes while modifying where the source volume type is gp3. Once the modification is complete, the impact to latency subsides. Your volume and any snapshots of your volume taken during this period are in a healthy state, and no action is required on your part. We are actively working to deploy a fix and expect completion in Q4 2021.
Thanks for coming to my TED talk.
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