Commenting widget in Editor can be switched on/off as much as required in Chrome/Firefox.
Although, in MS Edge, it works only once turned on and once turned off.
Page reload is required to make it turned on again.
Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.
This is known issue and our engineering team is investigating.
Please send email to email@example.com if you want to know any update referring SPM-7969.
KBA , BPI-SIG-PM-MOD-EDT , Graphical Editor for SAP Signavio Process Manager , How To