My 2 sims aren't siblings

[cutopia]

I am having a very severe case of this issue. I have made countless children with the same couple trying to get a pair of valid siblings. The couple was producing children from a single bassinet while living together in the same house while married. None of the children have been siblings even though they all list the two parent sims as their mother and father. This has been going on and on and on. I have bred close to a dozen sims and can't seem to get them to have the correct sibling relationship.

My player id is 1004086997203

Please someone tell me how I can finally generate real siblings?

[cutopia]

Note that I have also tried having two bassinets going. Early on I was moving kids out to a secondary house, but I stopped that and tried just having a nuclear family in the main house and generating the kids with one bassinet. I've been trying things like not making any changes to the sims' DNA once they age up. When I age up a new sim, I try to introduce them to all their siblings in the house, but none of them respond as siblings should... they all have the flirty options available and they all show up as acquaintance in the list of contacts.
If I try to do a rivalry relationship, the sibling rivalry is not available.

[jadyn143]

I have this same problem my ID: 1004108508507 

Please help !

[punkchic43220]

I’ve been having the same problem.  I even deleted the app and made sure the app was up to date but the problem hasn’t done away. Is there a fix for this? 

[simsinnyc]

Same thing has been happening. I tried many different ways. Made my sim had babies with another sim. Made two of my sims had babies. Made sims have babies as well as adopt babies. Nothing seems to work. 

[whackywhippet234]

I'm probally going to wait for my main family to have children. I will test this on my 2nd family to see if this is still any issue. Though, I'm trying to get the dad to move in but, will it being a love/hate story effect him being able to move in?

[violetpalomino]

I've been having this problem too. Since my Sims had children, I've grown them up and none of them recognize each other as siblings, but they all have the same mother and father, showing "mother" and "father" in their contacts. Their siblings are not in their contacts at all, and after introducing them, the Flirty option shows up and they are strangers/acquaintances. I've also tried to get the "Sibling Rivalry" story line to work, but it never shows up. 

My Player ID:1005045594935

[8w0qc8sb4cfq]

I have this problem too, but support doesn't help. Marvin, Janet and Willi are actually siblings, but are shown as acquaintances.

[SimGuruMaaike]

We've so far not been able to reproduce this issue, do you remember if you used the try for baby or the adopt a baby on the bassinet?

[cutopia1111]

I always use try for baby and never adopt. 

I even tried making a brand new sim instead of breeding one. I had that sim make babies with a friend’s sim and still the babies were not siblings!