Icons in Notification Area don't fit and have different sizes

I have a single panel, docked to the left, 70 px wide and with icon size in the Notification Area set to 22. I found out that with these values 3 icons could fit in a row. It was like that when I used Linux Mint since 2015 and last year when I installed Manjaro Linux. After some update late last year though, things went awry, as can be seen in the screenshot. The battery and Skype icons are larger than they used to be. No rows contain 3 icons, some 2, some just 1. I hoped it was just a glitch, to be corrected by another update soon, but still not, thus reporting.