Help with the jackal! (Warframe)

Hello everyone! I have such a problem, when I start (start) to beat the jackal, then after a while he just stops tightly and does nothing, you can attack him, but his health or shield does not decrease! At first they thought that when using abilities there was a lag with him and I decided to try it myself, I almost destroyed it, but when there was one blow left, it became! I don’t know why and I don’t know how to deal with it, maybe someone has already encountered this and decided!