[release-1.3] Changelog update reflecting recent patches 

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | -
| Fixed tickets | -
| Refs tickets  | #1601, #1599, 
| License       | MIT
| Doc PR        | -

Updated the changelog for the recent updates/patches to the release-1.3 branch. 
Not sure if these go in 1.3.7 or should go in 1.3.8 ?