How we decide who a coupon belongs to
The rule is simple: whoever actually brought the customer gets the coupon. The order in which this is decided is fixed in advance and doesn't change once the coupon has been issued.
The coupon was claimed via a partner's personal link
You clicked a real partner's personal link and got the coupon through it — the coupon is theirs, always. Even if you had previously clicked other partners' links.
The coupon was claimed another way, after you had visited a personal link
You got the coupon through the catalog, the market, or another platform channel — but within the last 30 days you clicked a real partner's personal link for this same campaign. The coupon still belongs to that partner (the last one whose link you used).
No personal link in the trail — the coupon belongs to the platform
No real partner's personal link was found — neither as the direct link used nor in the visit history within the lookup window — so the coupon is assigned to the platform's own channel (catalog, market, advertising), and the revenue from it belongs to the platform.
The decision is locked in at the moment of issuance
Who the coupon belongs to is decided once, at the moment it's issued — and never changes afterwards, even if there are later clicks on other links or the lookup window's length changes.