How can I fix this it keeps appearing.

Hole at the edge of vanilla Render Distance, especially during movement:

• Noisium
• Faster Random
  There is another mod that may help: . However, it can decrease DH generation speed by up to 35%.
  The easiest fix is to move slower and/or ignore it. This hole is most visible while moving over not generated (by vanilla) terrain. Moving over that terrain every subsequent time may not create the hole. And moving slower will give MC more time to load the chunks as you go.
  If none of that helped, you can also tune the overdraw prevention, look at the third section to know how.

• will mean DH LODs start where vanilla chunks end.
• will mean that DH render everywhere starting from your position.
  To fix this, you can either:
• Increase your vanilla RD, which will move the DH LODs further from you.
• Tune the Overdraw Prevention setting, see the next section to know how.