I have the same issue on Switch, Bedrock v1.14.30.
Every so often, after spending a night doing things in my (entirely closed off) house, I find creeper craters outside, up to several chunks away, even in lit areas. It's happening often enough that whenever I get around to filling them in, it takes less than an hour for another to appear, and that they accumulate quickly when I don't. It's frustrating beyond measure. I don't even feel like building anything anymore if it just blows up anyway, out of sight where I can't even stop it.
A few of the craters had iron ingots or stuck golems nearby, but neither should be attacking the other. If the creepers took collateral damage from a Golem's attack on a different mob, that could be part of the problem.
I have the same issue using 1.14.30 hotfix on the Switch.
I didn't really do anything much except carry them home, leave the game for a while, see the update, enter again, and find half my inventory full of stuck nests.
Seeing how the bee nests found in a new world I created with 1.14.30 work just fine, I think it got messed up in the update process.
Unless I am missing something, this probably has to do with the search range during portal creation.
Your overworld coordinates 7034.11 / 71.06 / -6008.15 convert to 879.26 / 71.06 / -751.01, but apparently the game could not create a portal there. Instead, it created a portal at a suitable place within the search range.
The coordinates of this nether portal at 850.50 / 34.51 / 673.50 convert to 6804 / 34.51 / 5388 in the overworld. Since your original overworld portal is too far from that location to be detected, the game created a new portal.
This is easily fixed by moving the portal in the nether to the appropriate coordinates.
Feel free to check the wiki at https://minecraft.gamepedia.com/Nether_portal#Portal_search_and_creation for more detailed info.