According to Hawaiian Volcano Observatory (HVO) a small lava pond developed near the western fissure during 5-7 March.
On 7 March at about 13:00 local time a levee of the pond started to collapse allowing the pond lava to drain into the main lake. The lake has developed a subtle levee on its south margin (just below the center of the photo), with several lava streams cascading down onto the lower level on the eastern end of the levee.
A new lava flow was active north of the normal lava flow entering the lake. This new lava flow was perched above the lake surface, and fed a narrow channel entering the lake. The new stream was set within a collapse scar that resulted from the collapse of a small lava pond.
Minor changes in the geometry of the western fissure, like this, happen occasionally.
Source: Hawaiian Volcano Observatory volcano activity update 12 March 2021