I have encountered a strange problem with SynEdit, when typing in a SynEdit, such as the Lazarus editor (and also one of the SynEdit demos) it displays each character typed on the keyboard as double characters. I see no similar effects in other components such as TMemo, or other software such as Xed, Libre Office, this edit window in Firefox etc.
The problem started after I rebooted after updating Linux Mint. I've tried rolling back to a past snapshot when everything worked fine, but no luck. I also upgraded to the latest Linux Mint 19.2, but same issue.
System: Linux Mint Mate 19.1 & 19.2. GTK2, Lazarus: latest trunk (r61909) and also Lazarus 1.8.2 (worked before). I think this problem made a brief appearance some time ago, but somehow it went away (hazy memory...).
I worked around the issue for now by switching to QT.
Any thoughts on how to get SynEdit working properly with GTK2?