See what I see as unneeded versions still kept - note the different library they come from - this is the 2nd time this has happened.

On Guests

VM2:~ # zypper se -si virtual
Loading repository data...
Reading installed packages...

S | Name                   | Type    | Version                         | Arch   | Repository
--+------------------------+---------+---------------------------------+--------+--------------------------
i | virtualbox-kmp-default | package | 6.1.22_k5.3.18_59.5-lp153.2.3.2 | x86_64 | openSUSE-Leap-15.3-Update
i | virtualbox-kmp-default | package | 6.1.20_k5.3.18_57-lp153.1.2     | x86_64 | openSUSE-Leap-15.3-Oss
VM2:~ # zypper rm virtualbox-kmp-default
Reading installed packages...
Resolving package dependencies...

The following 2 packages are going to be REMOVED:
  virtualbox-kmp-default-6.1.20_k5.3.18_57-lp153.1.2
  virtualbox-kmp-default-6.1.22_k5.3.18_59.5-lp153.2.3.2

2 packages to remove.
After the operation, 3.4 MiB will be freed.
Continue? [y/n/v/...? shows all options] (y): n
VM2:~ # zypper rm  virtualbox-kmp-default-6.1.20_k5.3.18_57-lp153.1.2
Reading installed packages...
Resolving package dependencies...

The following package is going to be REMOVED:
  virtualbox-kmp-default-6.1.20_k5.3.18_57-lp153.1.2

1 package to remove.
After the operation, 1.7 MiB will be freed.
Continue? [y/n/v/...? shows all options] (y):
(1/1) Removing virtualbox-kmp-default-6.1.20_k5.3.18_57-lp153.1.2.x86_64 .[done]
There are running programs which still use files and libraries deleted or updated by recent upgrades. They should be restarted to benefit from the latest updates. Run 'zypper ps -s' to list these programs.
 
VM2:~ #

On Hosts

LLR1:~ # zypper se -si virtual
Loading repository data...
Reading installed packages...

S  | Name                   | Type    | Version                         | Arch   | Repository
---+------------------------+---------+---------------------------------+--------+--------------------------
i+ | virtualbox             | package | 6.1.22-602.1                    | x86_64 | (System Packages)
i  | virtualbox-kmp-default | package | 6.1.22_k5.3.18_57-lp153.600.1   | x86_64 | (System Packages)
i  | virtualbox-kmp-default | package | 6.1.22_k5.3.18_59.5-lp153.2.3.2 | x86_64 | openSUSE-Leap-15.3-Update
i  | virtualbox-qt          | package | 6.1.22-602.1                    | x86_64 | (System Packages)
LLR1:~ # zypper rm virtualbox-kmp-default
Reading installed packages...
Resolving package dependencies...

The following 3 packages are going to be REMOVED:
  virtualbox virtualbox-kmp-default-6.1.22_k5.3.18_57-lp153.600.1
  virtualbox-kmp-default-6.1.22_k5.3.18_59.5-lp153.2.3.2

3 packages to remove.
After the operation, 88.0 MiB will be freed.
Continue? [y/n/v/...? shows all options] (y): n
LLR1:~ # zypper rm virtualbox-kmp-default-6.1.22_k5.3.18_57-lp153.600.1
Reading installed packages...
Resolving package dependencies...

The following package is going to be REMOVED:
  virtualbox-kmp-default-6.1.22_k5.3.18_57-lp153.600.1

1 package to remove.
After the operation, 1.6 MiB will be freed.
Continue? [y/n/v/...? shows all options] (y):
(1/1) Removing virtualbox-kmp-default-6.1.22_k5.3.18_57-lp153.600.1.x86_64[done]
There are running programs which still use files and libraries deleted or updated by recent upgrades. They should be restarted to benefit from the latest updates. Run 'zypper ps -s' to list these programs.
 
LLR1:~ #