have also encountered the same problem, where I could only shoot and detonate explosive barrels through remote weapons. only then can new explosive barrels be generated.
Generally speaking, this issue is not too serious, but in special circumstances it may lead to serious consequences.
When the player takes on the role of the Holy Grail Knight (other characters are played by AI), or when all members of the team have no ammunition, the drop of the explosive barrel in this position will cause the game to be unable to proceed.