[sylpheed:37055] GTK key bindings - lost control

Hi,
I'm running Sylpheed on a Linux Mint 20 machine and it seems I've lost
the control on the key bindings. Everything used to work, I have
"gtk-can-change-accels = 1" in my .gtkrc-2.0 but recently (maybe after
a usual software update) key bindings have changed together with a few
configuration defaults like "Auto wrapping".

Anyone pointing me to the right direction to get infos to solve the
issue? 

Thanks in advance