Yes, it's terrible. I started a thread about it here: https://community.phones.nokia.com/support/discussions/topics/7000011881 Unfortunately HMD seem to have no intention of offering a firmware fix – it's persisted from Android Nougat and across all the betas of Oreo so far. I doubt it's a hardware issue, so replacing it with another Nokia 5 is unlikely to make any difference. Hopefully your thread will get more attention than mine and the development team will at least pay the matter some notice. Otherwise, if you decide to keep the phone, just keep bugging them about it through the feedback app (like I have).
Due to Nokia's continued inaction on the issue and the numerous performance related problems with the Oreo update I have traded the handset on at significant financial loss. I contacted Nokia several times about the poor performance (especially on wifi), but had no response to my emails. The retailer was similarly unhelpful too. I will avoid purchasing a Nokia branded phone in the future. Very disappointed.