Hjdcti

Is there any reason why Cisco show run does not show the full version which is 16.3.7 in this example?

IOSSW#show running-config | include ersion
version 16.3

while show version does?

IOSSW#show version
...
Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 56 WS-C3850-48T 16.3.7 CAT3K_CAA-UNIVERSALK9 BUNDLE
...
IOSSW#

Is there any reason why Cisco show run does not show the full version which is 16.3.7 in this example?

For the simple reason that the only the major and minor versions are necessary for a complete understanding of the configuration. While there may be feature changes and/or enhancements between 16.2 and 16.3, changes in the build/revision should not impact the configuration in any way.

Stated another way, the difference from 16.3.6 to 16.3.7 may include fixes to caveats (bugs, flaws, and vulnerabilities), but this should not in any way impact what the configuration actually means to the device.

So when you do a show running-configuration it is helpful to know the major and minor versions to understand the configuration. However if you need the full version, you should use the show version command.

You are comparing apples and oranges. The show running-config command gives you a simplified version number that the beginning, but it is designed to show you the configuration, not the full version:

Current configuration : 15095 bytes
!
version 15.5

The show version command gives you more information about the versions in the device, but nothing about the configuration.

The two commands are simply aimed at different information. If you have a problem with that, you must take it up with Cisco. There is nothing we can do about it here.