1.9.1 - outnettcp got tcp error -1

[ѽ҉ᶬḳ℠ via Unbound-users]

On OpenWRT with: Version 1.9.1 linked libs: pluggable-event internal (it uses select), OpenSSL 1.0.2r  26 Feb 2019 linked modules: dns64 subnetcache respip validator iterator the log is full of: outnettcp got tcp error -1 and I am at loss what to make of that and thus to rectify? Help to get this sorted would be appreciated.