going up a size in shoe

i’ve been running in a size 9 for years and recently have been having toenail issues and feeling like my toes are too scrunched (i’m a 8.5ish size overall). i sized up to 9.5 in my saucony rides and they have been giving me foot cramps and weird stride stuff. has anyone experienced this? should that size bump make that much of a diff? the shoes don’t feel too big per say, just a little roomy. could my feet be “working differently” with the increased space? thank you for any info!