It is giving the sense that it is beyond my strength, beyond my capability. So it could be literally something physical but I think it would normally be applied to some objective which is seen as unachievable by the person speaking. In that sense the idea that "it is out of my hands" could also be a legitimate interpretation.
The idea that control over the situation has shifted to someone with more power or authority is certainly a possibility although that subtlety is not key to understanding the statement, C'est au-delà de mes forces. It is only saying that "I'm powerless to do anything about it" or "It's beyond my pay grade (authority)", etc. It could be for any number of unspoken reasons about which we can only theorize. "It's out of my hands" is essentially the classic "brush-off" for someone who, for whatever reason, will not give you what you want. I am not saying it is the best way to translate this because it is not a translation, it is an interpretation, as I said in my original post.
@ 1 km: I first thought to translate "beyond my strength" (singular). Knowing Duolingo I searched for a plural acceptable in this phrase, "strengths" not being one of them. I see that your translation uses the singular which means I was thinking along the right lines. Now we only have to convince the owl.
Interesting translation: " ... ce n'est pas au-delà de mes forces que de me répandre en larmes ... " = " ... I have been known to cry ..." found in the Canadian Parliament's Hansard reports. As these are official transcripts and Canada is officially bilingual, I think we must accept that this phrase can be translated in all sorts of idiomatic ways, as well as the literal. In other words there is no one correct translation, particularly for a fragment like this when taken out of context.
I think 'beyond my control' has a very different meaning. It takes the emph weird asis off one's own strengths or abilities (ie a personal attribution in psychology, to be technical) to something external (ie an external attribution). 'Beyond my strengths' is weird in English, where I think it would be 'beyond my abilities' which is accepted.