If a world is opened to LAN, it shows up on other games on the same network, even if they are not the same version. Unlike with servers, it does not tell you that the world is on a different version, and shows up as available.
If you try to connect with a LAN world on a different version, it obviously fails, but does not explain why, it only tells you that the connection failed.
MC-158582
Version mismatch ignored it LAN worlds causing unexplained connection issues
Resolved
Won't Fix
0
Can confirm; however the error message that shows up "Outdated version! Please use 1.14.4", or "Outdated server! I'm still on 1.13.2", respectively. That does explain quite clearly what's going on.
The core issue here is that in the server selection screen, it is not shown that the server is outdated, unlike all other servers in the list.