normally after an OTA update, it automagically installs the new build. 0.14-o-2021012798648-dev-herolte is a bit buggy, so it stops half way. The update installation must therefore be done manually.
Although the necessary installation steps have been mentioned several times here in the forum (Best regards from /e/forum ‘Search’), the following is a short version:
In TWRP tap “I
nstall” to navigate to the directory
/data/lineageos_updates and install the
.zip file from there.
But is it worth the effort? The /e/ROM does come with
microG version 0.2.17.204714-117, but only with
Android security patch 5 December 2020. Besides, /e/ has discarded the S7 /S7 Edge from its support list and so not much better will follow.
A release change (upgrade) could be a short-lived alternative. Forum member @LaurentG has thankfully been regularly building an [unofficial] /e/ OS ‘9-Pie’ for some months now.