I have no idea why OTA doesn’t work. No one has suggested a workaround which is why I’m manually updating by USB. I have tried rebooting it through web interface, powering it off. Doesn’t matter how many times, it just never works for me. I just get the Update Failed message. I’ve flashed it with the blank .bin file both times hoping it would make things different. I’ll check what my WiFi signal reports later but I don’t think that is the issue especially with such a small file too. So it has nothing to do with your version since I originally tried with the official v1.06. I started with v1.04 and have not been able to update OTA. Perhaps, the nodemcu version he used (Ray) previously had issues as I bought mine a tad over a year to the date. The last version I tried of yours was when you just added the garage door graphics but didn’t upload the graphic .bin file yet.
On the Blynk issue, I do remember doing something with battery optimization when I updated to Oreo. That isn’t the case for the tablet, however. I’m running Android 7.x whatever the somewhat current build (within a month) of LineageOS.