Preboot, ISCPreboot, Xart, Hardware, VM, Update ejection issue when ejecting a volume

I wanted to unmount an encrypted local volume on my Mac. it told me that the disk was busy and I wanted to force eject.

several popup appeared indicating that the discs could not be ejected because in use.

I don’t know how these volumes work, but it worries me.

PS . The Mac has just been reformatted and EtreCheck is showing high memory com.apple.WebKit.WebContent when there was not too much activity.

Do you have any explanations?

Thank you in advance