Swiss cheese plant

I love my Swiss cheese plant and have had it about 2 years. The occasional brown/yellow leaf spots are disappointing. Not always just tips as you can see from the other photos. I have it in a good chunky mix soil & water when the top inch or two is dry. Fertilize during growing periods. It is quite close to a large north facing window. It just got its largest leaf ever so I think it’s happy but would LOVE to prevent these brown edges. If anyone has suggestions I would love to hear them. Thanks!