FWIW The last time I had that problem I….
Cut out all the browning leaves.
Upped the ferts, especially K and the micros
And increased the water changes.
I do think it might be related to the algae which is why I cut out most of the discolored leaves. I increased the ferts at first doubling the amounts. This was followed by an outbreak of various green algae. So I kept doing weekly water changes and reduced the dosing but kept the k and the micros high.
I do think it likes the higher temp but I can’t say for certain.