3DS transactions essentially enforce Multi-Level Authentication (MLA).


MLA transactions usually take more than 10 seconds to get completed. However, MLA is applicable only for transactions during subscription creation. According to Strong Customer Authentication (SCA), recurring transactions that are authenticated during subscription creation, do not have to go though the 3DS flow again.


Also, please note that there is a minor chance that the issuing bank might enforce 3DS on selective recurring transactions on a case by case basis; However, this is entirely subjective and based on the issuing bank protocols.