Issue receiving group messages on android device after recent switch

Hi, so I recently switched over to an android device and now I'm not receiving messages from anyone in my old group threads that is using an iphone running any version of ios8. I disabled imessage before switching over. I've been on the phone with apple support and they've assured me that my number is no longer anywhere in their system. I tried resetting my apple id password. I've also tried having individuals in the group delete the thread and then re-make the group before texting it again, which worked for a time, but then switched back to them sending imessages and me not receiving them. The really weird part is that I still get group messages in these threads from users with iphones that have not yet upgraded to ios 8. Has anyone out there heard of anyone experiencing the same thing or have any suggestions for me on how to resolve this issue?

Thanks!