Using Redirects obliviously you need technically reported to search operating systems (search engines) after bringing some changes usually forwarding the pages URLs from old to new as example.com/old as example.com/new and they five in number (301, 302, 303, 307, 308).
Using 302 mean to tell search engines for a temporary change like to telling someone about you are going some where but you'll be back soon to previous.Here is some problem while using 302.
The problem concerns for carrying 302 redirect for forwarding example.com/old to example.com/new then the redirects from one domain example.com/old to another domain example.com/new that you are claiming for temporary change, that is, the web server on old url will come up to show the new changes but soon the changes will cancelled and web server start showing content on old again, but here Google started to remove the original destination URL from it's index results by first stripping the title tag and leaving this message as the meta-description "A description for this result is not available because of this site's robots.txt.
Suppose you carried 302 for as, example.com/old is being redirected to example.com/new, but new destination URL is being blocked in robots.txt. That means the old URL has been removed from Google and replaced by nothing or will the original URL/NEW continue to be listed as is by removing the old.
Using 302 mean to tell search engines for a temporary change like to telling someone about you are going some where but you'll be back soon to previous.Here is some problem while using 302.
I am under the impression that when a 302 redirect is being carried out, Google is supposed to keep the original URL listed in its index (example.com/old), while crawling the content on the forwarded URL (example.com/new). However, if the forwarded URL is being blocked by robots.txt, then the original URL will be removed from Google's listings and replaced by nothing.
The problem concerns for carrying 302 redirect for forwarding example.com/old to example.com/new then the redirects from one domain example.com/old to another domain example.com/new that you are claiming for temporary change, that is, the web server on old url will come up to show the new changes but soon the changes will cancelled and web server start showing content on old again, but here Google started to remove the original destination URL from it's index results by first stripping the title tag and leaving this message as the meta-description "A description for this result is not available because of this site's robots.txt.
Suppose you carried 302 for as, example.com/old is being redirected to example.com/new, but new destination URL is being blocked in robots.txt. That means the old URL has been removed from Google and replaced by nothing or will the original URL/NEW continue to be listed as is by removing the old.
If you are sured about using 302 then it is truth that it has nothing to do with robots. /old will stay because a 302 is a TEMPORARY redirect so you're asking Google to keep the old URL in the serps.
However, if the forwarded URL is being blocked by robots.txt, then the original URL will be removed from Google's listings and replaced by nothing.
It might be possible that you disallow in robots.txt for the forwarded URL with a noindex and/or change the redirect type to one in javascript or perhaps the problem is due to 301.