Several possibilities. Maybe the stropping dulled the edge, maybe waiting 7-9 days presented too much beard for your shaving abilities,maybe you were more inconsistent with technique the second time.

Too many folks think they shave once or twice and they have straight shaving licked. That is folly. Most of us will tell you that.

As far as rust goes, just dry it as good as possible {I use a stropping motion on some soft terry cloths} and let it air dry. If need be you can coat it with oil on a daily basis. Just make sure the razor is removed from any humid environment.