Unfortunately there could be a lot of reasons for that to happen.
We don't know the reasons behind your particular problem and it helps us to have as much information as possible.Please read this forum guide for what information you should give with any question you wish answered or your post may get ignored by those that could help,
Post back with the information and we will see what can can advise.
I'll guess you have Magix Movie Edit Pro 2022 or Magix Movie Studio 2022.
If you have, have a play with these settings:
Quite a few people have had "trouble" with this and it has been resolved by switching to different options. For example, switch all options to CPU and see how you go.
While, at times, the problem has been old equipment, graphics card drivers (both integrated GPU (Intel igpu) and third-party PCIe cards eg GTX 1050) have also caused problems like this, so make sure those drivers are up to date.
Intel igpu drivers (general start page, navigate to your specific setup):