Happens every time during OFX import on windows 10 Gnucash 3.1 and 3.2. Happens on two separate computers as well. I have an overly sensitive trackpad which is how I discovered this problem. Start by importing an OFX file. Within the transaction matching window, click and drag an item to a another line in that window. The transaction will now be duplicated (Is that a bug too? I haven't filed that one because I wasn't sure). After a transaction has been duplicated in the OFX matching window, upon accepting or cancelling the transaction matching window, GnuCash will crash.
Added possible fix to PR432. This did not happen on my Linux box but was observed on Windows. This seems to be related to 'drag and drop' and as that has not been setup I have expressly disabled it with a gtktreeview function call.
The fix was accepted and will be included in GnuCash 3.4. Thanks!