Mission bug - Enemies not respawning

I ran into a bug in Grounded 2 where I completed a mission that required killing some special insects. These insects only spawn in a specific area, and I already killed them and collected the materials.

Later, the same mission appeared again, but now the insects don’t respawn, so I can’t complete it. I also don’t have a save file from before killing them.

Is this a known issue? Is there any way to fix or reset the mission?

Thanks in advance for any help or info..