It was a bug. Apparently it was also an exploit.

[Current Known Issues]
■It is possible to avoid knockback effects of actions used by enemies when using certain general actions such as desynthesize and repair during combat. *Please do not attempt to exploit this bug when progressing duties, as exploitation of bugs falls under prohibited behaviors.
Why are you even here then?
Is this an existential question?

Yeah he wrote "P12" not "P12S". Seems like Vel can only fathom a bug needing to be fixed when he personally encounters it and to the obvious "it will get fixed".
As to how long it will take?

*This issue is related to core processing, including action execution and battle related processes, and since it involves an exceedingly wide scope of investigation and correction, it is expected to take some time to address the issue. Therefore, we have implemented a temporary measure only for Pandæmonium: Anabaseios (Savage), which has just been released and has been greatly affected by this issue. We will officially announce the details and timing of the fixes as soon as they are finalised.
Source:

https://eu.finalfantasyxiv.com/lodes...55464c94d5dded

So yes it will be fixed, this is an interim measure.