I can reproduce this with firefox-esr 60.5 on a Cubieboard 2 running Stretch/armhf. However, in a Buster/armhf chroot Firefox works fine.
To make sure this is not a chroot effect I tried again in a Stretch/armhf chroot and it shows the same error as the Stetch/armhf host. For sake of completeness I repeated the same in Stretch and Buster/armel chroots and got the same results as in the respective armhf counterparts. So I'd conclude this problem is specific to the Stretch/arm* architectures.
