It used to be you can peak anything by shift + right clicking it then you can look at the other side for a pretty long time. But now if you peak a cave sometimes it works as intended and other times it just sends you straight through after a couple of seconds.
Happens on default client, repro steps appear to be this:
Find a cave, peak and go through, then peak and exit the cave. Then when you peak the cave the bug will trigger.
short video here showing the time frame once bug is triggered,
https://i.imgur.com/Yi6EKQh.mp4
Doesn't happen with stone mansions or mineholes. haven't tested anything else