The issue below is, what I believe to be, a Firefox bug:
Buttons located ANYWHERE on the navigation bar's main section are constantly being shoved off into an overflow drop–down menu (double–arrow) towards the right end. Going into/exiting customization can be used as a temporary fix - as it removes the drop–down arrow and puts the button icons back where they were in the main section; over time though, the icons inevitably get pushed back into this drop–down menu.
------------------------------:arrow_double_down:--------------------------------------------:arrow_double_down:------------------------------
Now on to Puzzle Bars with Beyond Australis:
Slim Chrome makes the Top Puzzle Bar's buttons behave just like in the bug above. True to form, when coming out of the customization interface there is no longer a drop–down arrow; but unexpectedly - instead of all the proper buttons being placed back onto the toolbar - only the buttons that were hidden inside that drop–down are now present; while the ones which had still been visible after the drop–down appeared are GONE FOR GOOD. A Firefox restart is all I can do to get them back… disabling/enabling PB or BA won't bring them back unfortunately.
------------------------------:arrow_double_down: hover each image to see descriptive text ⏬-------------------------------
✔️ All my buttons

👊 Notice the double arrow on the right side

🚫 WTF! Where'd they go?

disabling 'slim chrome' will automatically vanish my buttons; also note that entering customization makes the same misfortunate buttons disappear — whether the toolbar overflow error has occured or not
Win7 Pro 64-bit ¦ Firefox 49.0.2 ¦ Puzzle Bars 2.1.15 ¦ Beyond Australis 1.4.6
The issue below is, what I believe to be, a Firefox bug:
Buttons located ANYWHERE on the navigation bar's main section are constantly being shoved off into an overflow drop–down menu (double–arrow) towards the right end. Going into/exiting customization can be used as a temporary fix - as it removes the drop–down arrow and puts the button icons back where they were in the main section; over time though, the icons inevitably get pushed back into this drop–down menu.
------------------------------:arrow_double_down:--------------------------------------------:arrow_double_down:------------------------------
Now on to Puzzle Bars with Beyond Australis:
Slim Chrome makes the Top Puzzle Bar's buttons behave just like in the bug above. True to form, when coming out of the customization interface there is no longer a drop–down arrow; but unexpectedly - instead of all the proper buttons being placed back onto the toolbar - only the buttons that were hidden inside that drop–down are now present; while the ones which had still been visible after the drop–down appeared are GONE FOR GOOD. A Firefox restart is all I can do to get them back… disabling/enabling PB or BA won't bring them back unfortunately.



------------------------------:arrow_double_down: hover each image to see descriptive text ⏬-------------------------------
✔️ All my buttons
👊 Notice the double arrow on the right side
🚫 WTF! Where'd they go?
disabling 'slim chrome' will automatically vanish my buttons; also note that entering customization makes the same misfortunate buttons disappear — whether the toolbar overflow error has occured or not
Win7 Pro 64-bit¦Firefox 49.0.2¦Puzzle Bars 2.1.15¦Beyond Australis 1.4.6