Can anyone recommend a mobile phone with the following features?
* no Google services (e.g. by running an alternative rom)
* not too expensive (it's for children)
* not too bulky
* gets updates
* runs Signal
* at least 4G
* not produced by Google => no Pixel devices

EDIT: * no iPhone

I still own a Samsung A3 2017 which would fit those requirements. Unfortunately, I did not manage to flash it with an alternative rom.

#PurchaseRecommendation

@a32 Depends on how much is "too much". I've recently got my SHIFT6mq and am quite happy with it: Google-free ROM provided by manufacturer, flashing as easy as downloading on-device and triggering a "local OTA". EUR 650 might be a bit high, but they also have the SHIFT5me (EUR 350).Still stuck at Android-8, though – but rumors have it there's "light at the horizon" for the G-free variant.

They also sell refurbished, but a long wait list for that.