Recently I gained access to Tomb of the Nameless in Avalon, however, upon entry by myself, I encountered an issue with the first battle. Upon defeating a Disloyal Knight enemy, it respawned slightly behind the battlefield, and upon contact, joined the battle as an additional enemy would. This process seemed to repeat the first two times I defeated a Disloyal Knight, after which I fled.
Normally not more than two enemies should be able to join a solo battle, but a total of four were in the battle the last time I tried. What's going on here?