I now tried Rebirth 4 times and only the very first time was successful. I could reconnect with all my friends and family members.
I used the same sim all 4 times. No additional conditions.
First time, I chose to "rebirth" her into her friend family without actual family connections (as YA). It all worked as intended.
Second time I chose the same family, but made her friends her relatives. She didn't recognise any of her previous family, including parents, brothers, sisters, cousins etc. She did recognise her friends (now her sisters) though.
After that, I've tried to replicate my first time. And each time she just recognises 2 of her friends in whose family she reincarnates despite they are just friends, i.e no family connections. She can't "remember" anyone from her previous family and even can get romantically involved with any of them.
The only thing that was different the first time (and the reason why I replayed it) is that I forgot her urn in her inventory and it was lost. All other times it was preserved. Not sure if it matters though.
Edit By Crinrict: Adjusted Title fit migrated bug report: [LD] Relationships lost with sims after rebirth | EA Forums - 11708958
Archived thread had around 0 me toos
