That’s quite odd since there was no Foreman 2.6.0 release 
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I assume you are running an old nightly build that had a bug which was fixed in Refs #32840 - Fix setting editing by tbrisker · Pull Request #8664 · theforeman/foreman · GitHub
For production use it’s recommended to use only stable builds, the current version being 2.5.2 right now, with 3.0.0 coming out soon (there is already a release candidate).
