I rooted my Xperia SP and had installed the Cyanogenmod 11 (last stable-ish release, milestone or something) successfully.
After being encouraged by a co-worker that the nightly builds are pretty safe too, I installed a 12.1 nightly (can't remember which, though).
After that I couldn't reboot to bootloader any more to back up my phone.
I can select it in the reboot menu, but the phone will just cycle into a normal reboot and start Cyanogen.
Being brave I installed another nightly (current version: 12.1-20151010-NIGHTLY-huashan), hoping that would help.
It didn't, but luckily that version works, too.
Otherwise the phone works well, but I would like to be able to reboot into the bootloader to create a system backup, before I install more nightlies.
Rebooting into recovery works. However, have no backup option there.
To clarify: booting into bootloader is not necessarily what I want, it's the backup option that I'm after.
On the other hand, this not working properly is kind of a red flag, so I want to make sure nothing is going sideways...
Any advice would be much appreciated!