We rolled our stats, and long story short my fighter has a Wisdom of 4, so the modifier is -3. 

I still took proficiency in Perception to help counterbalance that -3. My proficiency bonus is +2 so I would expect my Perception rolls to have a -1. However, it's showing up in my character sheet in D&D Beyond as a +1.  

Is there a rule against having a negative modifier for a skill you're proficient in, or is this just an error? 

What race? Does your character have a racial or other ability raising the Wis to 6? Do you have any class features or feats that give you a bonus to Wis or Perception? 

If you tap that Wis Save, it should tell you how it added up to that.

Quote from thatssochouette >>

We rolled our stats, and long story short my fighter has a Wisdom of 4, so the modifier is -3. 

I still took proficiency in Perception to help counterbalance that -3. My proficiency bonus is +2 so I would expect my Perception rolls to have a -1. However, it's showing up in my character sheet in D&D Beyond as a +1.  

Is there a rule against having a negative modifier for a skill you're proficient in, or is this just an error? 

 The only thing that I could think of would be expertise, but on a fighter... are you a human variant with prodigy?

Thanks, I was able to tap on it and figure out how it added that up!

It was a magic item from our DM in my inventory that added to perception. I feel silly, but I hadn't noticed that it was equipped. Thank you both very much for your help! 

Happy to help

Quote from thatssochouette >>

Thanks, I was able to tap on it and figure out how it added that up!

It was a magic item from our DM in my inventory that added to perception. I feel silly, but I hadn't noticed that it was equipped. Thank you both very much for your help! 

 Bonus magic items that you knew nothing about... your screen name is very appropriate for that.