The bug
In version 1.14 the glass panes decides to connect to the sea lanterns instead of creating a clean row as it used to in the last versions.
Version 1.13:
[media]Version 1.14:
[media]Linked issues
Attachments
Comments 10

Almost certainly intended behaviour given the changes to transparent blocks in 1.14
Can confirm in 20w51a.
Can confirm in 21w03a.
Can confirm in 21w06a.
Can confirm in 1.16.5 and 21w08b.
Can confirm in 21w11a.
Can confirm in 1.17.1.
Can confirm in 1.18.2.
Can confirm in 1.19.
This affects glowstone as well.