If it is a gift ASA rules do not apply (the flow chart clearly shows this), it is covered by the CMA.
CMA - If you have received or been promised any form of payment or other incentive.
The CMA takes the view that ‘Advertisement Feature’ or ‘Advertisement Promotion’, are useful descriptions, but it has seen a range of other wording, (including #Ad, #Advert, and using the ‘Paid Partnership’ tool on Instagram in addition to these hashtags), which convey the appropriate messages simply and effectively.
Haven't see #gift mentioned anywhere by the ASA or the CMA, which I think is why the influencers are quite angry.
It is not lost on me that last year many bloggers/influencers wrote that they would not be using 'gifted' or declaring gifts as they didn't think we needed to know.
Now that they have clearly been told to use Ad/Advert for everything they are back tracking and now suddenly want to use #gift. You couldn't make it up!