Problem when Join (as karaoke)

[moi15moi]

If I join these two lign with the option Join (as karaoke), it add {\k214} for no good reason a the beginning of the subs.

Base:

Dialogue: 0,0:21:18.86,0:21:21.00,ED,,0,0,0,,{\k50}Ko{\k47}no {\k51}ki{\k26}mo{\k40}chi
Dialogue: 0,0:21:22.78,0:21:25.26,ED,,0,0,0,,{\k34}ko{\k20}{\k49}i {\k24}de{\k54}su {\k67}ka

Result: Dialogue: 0,0:21:18.86,0:21:25.26,ED,,0,0,0,,{\k214}{\k50}Ko{\k47}no {\k51}ki{\k26}mo{\k40}chi{\k248}{\k34}ko{\k20}{\k49}i {\k24}de{\k54}su {\k67}ka

What I should receive: Dialogue: 0,0:21:18.86,0:21:25.26,ED,,0,0,0,,{\k50}Ko{\k47}no {\k51}ki{\k26}mo{\k40}chi{\k248}{\k34}ko{\k20}{\k49}i {\k24}de{\k54}su {\k67}ka

If you want to test, here is my .ass: https://mega.nz/file/DxFQlLiA#h2LMMGIt5Zy8NXA60LRMuenw2OP6ELPONWawumZZaWY

[Ristellise]

Seen this bug a couple of time already, I'll look into it when I have the time.