Delimiter issue in 2.3.6.1

[Paul A. Rubin]

I'm using LyX 2.3.6.1 on Linux Mint, and I just tripped over a possible 
(minor) bug that I'd like someone to confirm. Create a math inset and 
click the toolbar button to insert paired delimiters. The lfloor and 
rfloor delimiters look correct to me, but the lceil and rceil delimiters 
are just vertical lines (no horizontal "flanges"). Anyone else seeing that?

Paul