Being "invisible" is not the same as being "aethereal". The two terms are not synonymous.
Jesus walked with them the whole time, invisibly, being with them, then made himself known, then at the supper disappears again, being invisible (can't be seen). He did not phase through a door, wall, etc. He (Jesus) went back with them (two from Emmaus from there back to Jerusalem, when they were let in), then revealed himself in their midst.
The same with the resurrection. Gabriel came down and rolled away the stone, so Jesus could walk out. Same with the other resurrections that day, their stones were previously removed on the 6th day at the earthquake, so on the first day, when resurrected, they could get up and walk out. No on phased through walls, teleported, or other. They have real bodies as did Moses and Elijah on the mount of Transfig.
I am not questioning 'mortal' or 'immortal'. Jesus has a glorified "body", with "flesh and bones" (Luk. 24:39). He ascended back to the third Heaven, and did not phase into the universe as a mist and evaporate as perfume.