Verb for action; "Actioning"

Solution 1:

A) "Can you please fix this?"

B) There are verbs related to action. As John Lawler says, the root of action is the verb act. But act is intransitive, so it can't be used in this kind of phrase - you cannot act a fix.

Another verb related to act, enact, is transitive, and its meaning more-or-less fits this context:

enact

2 Put into practice (an idea or suggestion)
‘the pressure group's aim was to see the proposals enacted’

https://en.oxforddictionaries.com/definition/enact

It is grammtically correct to say, "enact a fix," but it's not idiomatic. Perhaps because fix is already a verb.

Solution 2:

"Act" is a verb; its noun is "action". You cannot use a noun in place of a verb. If you mean fixing something, politely and professionally, you can say:

--I was wondering if you could kindly fix this/this issue.

--Is it possible for you to kindly fix this/this issue?

--Could you kindly fix this issue (as I am not able to do so)?

The sentence "please consider actioning a fix" is by no means grammatical or even professional.

Hope this helps!