Rooted phone, cannot mount /system as rw
I have rooted my phone, it has /system/bin/su but I am unable to actually utilize its functionality. For example, I cannot install openvpn, busybox, a custom /etc/hosts file.
I can run adb remount and when I run "mount|grep system" it shows it being mounted as rw. Then I can write files as normally, but when I reboot, everything is back to its default.
Output of mount|grep system:
/dev/block/mmcblk0p33 /system ext4 ro,seclabel,noatime,data=ordered 0 0
After running adb remount:
/dev/block/mmcblk0p33 /system ext4 rw,seclabel,noatime,data=ordered 0 0
But when I install busybox, nothing is installed into /system/xbin
Anyone know what is up? Using HTC Sense 5.5 on an HTC One mini.