I am hosting a sevtech server for my family and we have created several portals up to Stage 2 (the beneath, hunting dimension, the betweenlands, and the twilight forest). All of the portals work fine for me (I am connected locally), but the portals that do not require you to 'sneak' to enter (the betweenlands, the twilight forest) do not work for the other 2 players (who are connected to the ip remotely).

For example, when standing in the betweenlands portal, both players reported that the screen fades to green, but they never get a loading screen. However, the beneath and hunting dimension portals which require you to 'sneak' do, in fact, work correctly.

I attempted to remedy this by teleporting them using the tbteleport command (which worked fine for my character) - however they both receive "teleport successful" but remain in the overworld.

Also, no errors or prompts of any kind appear on the server console when they attempt to use the 'non-sneak' portals.

As of right now I have no way of getting them into these dimensions to help me advance through achievements, and I cannot find any other instances of this issue anywhere on the internet.

Thank you in advance for your help!

First of all, your report seems to imply you are using "Open To LAN". This does not work well in modded Minecraft. I would recommend you host a dedicated server, in most cases a system capable of running a Minecraft client is also capable of running the client and server at the same time. It requires a little more RAM, but little overhead otherwise. If you need support with setting this up, you can get support in https://discord.gg/darkosto

Second, some dimensions are locked behind the players unlocking the relevant ages. Can you please verify that all players are in the same age, and that the output of /gamestage info indicates this?

I'm not using open to lan. I'm hosting a server on my private server blade on my local network.

I resolved the issue by revoking all advancements and having the other players /tofe forcesync

Apparently they had been getting the advancements but not moving up in age properly - therein lies the bug.