Select factory app without erasing oat_data

[futuredesign]

Hi,

I have an application with factory, ota_0 and ota_1 partition. I use the factory app for uploading new apps to the two oat partitions. When I need to update the oat app, then I select the factory partition for boot and then reboots. On the next boot it's the factory app that is running just as expected... however the oat partitions are invalidated. How come a esp_ota_set_boot_partition call invalidates the oat apps?
It makes no sense to me.

Thank you in advance.