@roo what version of /e/ do you use ?
what is the actual baseband ( Samsung / android level version )
You could try the latest /e/ 0.18 oreo dev official installed on a fresh android 8 based device
Info about Samsung Galaxy S7 - herolte
https://images.ecloud.global/dev/herolte/
[HOWTO] install /e/ on a Samsung device from a GNU/Linux PC successfully