Did you ever figure out the "low write speed" on your drive (https://hardforum.com/threads/hot-inland-1tb-nvme-premium-107-99-microcenter.1978390/page-29 )? I am running into almost the exact same behavior - drive (1TB) tested at rated speeds on purchase. Drive is now about 50% full - will do 3400read/1000write about half the time in CrystalDiskMark, then sometimes it runs just fine...
Thanks
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