We actually had this issue in 20w16a, but didn't see anything about it in the 20w17a update.  On our server, we decided to delete our nether so that it could regenerate with all the cool new biomes and structures.  When we entered the nether, no portal generated on the other end. We could walk through and throw items through, but they would just appear in the nether where the portal should have been.  We've deleted the nether once before in one of the first snapshots and didn't have any issues.