I don't know where you are (I assume it is Sweden maybe?) but here is a link that shows the frequency bands supported by your phone (it is a Huawei Honor 8 isn't it?) and also the bands supported by both Telia and Telenor, (scroll down to find the two carriers). It may be that the area in which you are that Telenor does not use a frequency compatible with your phone, e.g. Telenor doesn't support LTE B20 signals but Telia does and maybe that is what is being used in your area.
Hi,
I don't know where you are (I assume it is Sweden maybe?) but here is a link that shows the frequency bands supported by your phone (it is a Huawei Honor 8 isn't it?) and also the bands supported by both Telia and Telenor, (scroll down to find the two carriers). It may be that the area in which you are that Telenor does not use a frequency compatible with your phone, e.g. Telenor doesn't support LTE B20 signals but Telia does and maybe that is what is being used in your area.
https://www.frequencycheck.com/compatibility/o1QbSB7/huawei-honor-8-dual-sim-td-lte-frd-al10/sweden
It might also be that it is a faulty SIM card. Can you prove that it works by inserting it in a Telenor network compatible phone?