For the main translation of 下がる, we have “To get lower”, and for 上がる, we have “To go up”.
But “To go down” is not in the answer list for 下がる, and the same with “To get higher” for 上がる.
Shouldn’t the translation of 下がる be “To go down”?
This has already been discussed on this topic Acceptable meanings for 上がる but nothing changed.
Yeah, that’s definitely worth a look into, if only for consistency’s sake. That said, it’s not entirely clear from that thread whether anything was done to draw the attention of those who could effect changes. For example, tagging the @Mods 
Thanks for bringing this to our attention! I’ll share this with the team and see if we would like to add some alternative meanings or regular meanings to the mix.
I feel like with the words"to get" implies you are doing the action(transitiveness),and these are intransitive verbs. So, I can see why that may not work.
Hi there! I wanted to update you on your suggestion and let you know that the team took a look and made some changes. For 下がる, we’ve added “to go down” as an alternative meaning, moved “to fall” and “to drop” to the allow list, and updated the meaning explanation. For 上がる, we’ve added “to get higher” as an alternative meaning, moved “to be raised” to the allow list, moved “to stop” to the warning list, and updated the meaning explanation.
“To get lower” is intransitive because it doesn’t can’t take an object.
I get lower.
The flag gets lower.
*I get lower the flag.
So “to get lower” still works for 下がる. 私が下がる = I get lower/I go down, 旗が下がる = the flag gets lower / the flag goes down, etc.