https://wccftech.com/nokia-7-plus-units-running-android-p-experiencing-major-issues-after-receiving-the-june-security-patch/

It isn’t unusual for a monthly security patch to cause some minor bugs in an otherwise operational device. We’ve seen it happen time and again with Pixel phones and even HMD Global’s own Nokia 6.1, which suffered WiFi issues post the May security update. However, it is a bit of a concern when an OTA update completely wrecks your phone, rendering it unusable. Several users running the Android P Beta on the Nokia 7 Plus were in for a rude shock when they discovered that their device was unusable after installing the June security patch.  According to a complaint on the Nokia forums:

Same problem after installing security patch and finishing reboot it showed .com.androidphone stopped working and I had to hard reset after that it became Oreo 8.1