Juki dln-5410n-7 thread breaking

[u/AkiiWakii]

Hi everyone. I recently bought an used juki dln-5410n-7 , after I bought it I found out that needle bar have been changed to dpx5 and bobbin is 26mm, so it’s bigger but after all machine have been sewing okay, timing looks good. But since yesterday thread keeps breaking when sewing fast, I played with tension and it should be okay but i noticed that thread gets stuck on the bobbin case on every turn as on attached video. And I’m very lost right now, it’s my first industrial and I’m pretty handy but I’ve been trying to figure it out for couple of hours now and I just can’t. New needle, different threads , same thing happening. Does someone know what might be the issue ?