Had similar while hiring for a Sr Dev. The person who first joined the call was not able to articulate any of the frontend or backend work they had done at the previous contracted company.
Call goes static, call drops.
"Person" rejoins. Who is obviously a completely different person who was able to thoroughly fill in the previous details missed.
We ended the call there. Mistake: didn't require video for the session when the first individual proclaimed they were having issues with video.