On Sat, 27 Feb 2021, Rocco Roberto Mosconi wrote:
 When I click for example on the blue arrow to select the dependent 
 variable nothing happens (the variable is not written in the 
 appropriate space). Same for the green arrow selecting the 
 regressors [...]
 [T]he problem arises only if you share the entire screen/desktop. 
I just tried this (using gretl's variable-selection arrow buttons 
when sharing my entire desktop) on both Zoom and Jitsi and there's 
no problem. So I guess this must be specific to Webex.
Allin Cottrell