If you uninstall AE CC 2015, you can reinstall it without any updates.
If you're looking for CC 2014, try this link's directions: http://blogs.adobe.com/adobecare/2015/06/16/how-to-find-and-install-previous-version-of-ad obe-apps-in-cc-2015/
If you'd like to help us to test the After Effects CC 2015 (13.6.1) update---which fixes the bugs that you mention---you can request access to the prerelease testing program here:
Choose the "Private programs" tab and click Apply to apply for the "After Effects CC 2015 (13.6.1) patch update" program.
The After Effects CC 2015 (13.6.1) bug-fix update is available. It fixes several bugs, including the one being discussed on this thread.
Let us know how things work after you have installed the update.