I believe the Temu ads (or any that are 5 seconds) don't give the reward. Below you can see a video of 2 Temu ads where I didn't receive a green pack.

I cleared my cache and started having 30 seconds adverts which I was rewarded for. Eventually I began getting the Temu ads again and didn't get my green packs again. Watched 3 in a row and none of them gave me the reward.

You can skip the first 20 seconds whilst it's loading the ad https://streamable.com/167x4u