After upgrading my system to Ubuntu 20.04 and using latte-dock 0.9.85+git20200425.1355-0~ubuntu19.10~ppa1, right-clicking anywhere on panels or plasmoids does nothing. I'll double-check and amend this report afterwards, but I'm pretty sure the right clicking was still working before enabling the latte PPA and upgrading, that previous version was presumably 0.9.7
Problem doesn't arise any longer after latest `apt upgrade`. Closing.