Question About the problem of spotlight shadows away from the origin.

Hello everyone!

We will consult only if there is a problem that cannot be solved for many years.

Real-time shadows of spotlights far from the origin are not displayed well.
Like in the video, shadows may or may not appear depending on the direction of the spotlight.



This phenomenon seems to occur when the distance from the origin is 2000 to 3000 or more.
The video is from Unity 2020.3.18f1, but this reduction occurs in any version.
It also occurs in both Forward and Deferred.
Similar problems do not occur with directional lights and point lights.

Is there a solution to this problem?
If you know, please help.

This sentence is machine translated from Japanese to English, so it may be unnatural, but please forgive me.