No, your eyes are not deceiving you. This code looks near similar to another one PLUSA5 but works on a different set of "eligible" sellers, mostly private sellers for both new and used items.
Offer Period. This offer commences at 5:00pm AEDT on 1 April 2022 and is available for a limited time only (“Offer Period”). eBay reserves the right to cancel the offer at any time.
Eligibility. This offer is available to eBay Plus members only.
Conditions. This offer entitles you to 5% off the pre-coupon purchase price (excluding postage costs) on Eligible Items during the Offer Period, when you spend $15 or more (excluding postage costs) in one transaction, up to a maximum discount of $1000 per transaction. Multiple items may be purchased in 5 transactions (up to a maximum of 10 items per transaction).
"Eligible Items" means items listed on eBay.com.au where a link to these terms and conditions and the coupon redemption code PLUSAA5 is found in the item listing.
Redemption. To redeem this offer during the Offer Period, enter the redemption code PLUSAA5 into the redemption code box during checkout. This code cannot be used in conjunction with any other eBay offer, coupon or voucher. You can only use the redemption code 5 times during the Offer Period. The code is provided to you as an eBay User and the limitations on its usage apply on that basis even though you may have registered a number of different eBay User IDs.
[Edit 10/4/22:] Another 5% "eligible" code PLUSAAA5 was identified by pamer.
No offence OP, but this is hardly a deal, considering eBay