Strange behavior when using mapping within a sitemap

I observed a strange behavior when editing my main sitemap. I think I did not have this issue before upgrading to 3.4.0 (but I am not sure 100% since I do not make change to my sitemap on a regular basis). I have the following mappings:

        Frame label="Heure de réveil" {
            Selection icon="clock" item=Heure_Selection mappings=[0="6h45",1="7h00",2="7h15",3="7h30",4="7h45"]
        }

When I save it and reload it, the quotes (") disappeared and the code editor complains about it

Error: Syntax error at line 325 col 80:

                  Selection icon="clock" item=Heure_Selection mappings=[0=6h45
                                                                                 ^
Unexpected identifier token: "h45". Instead, I was expecting to see one of the following:

I cannot add the quotes with the code editor since it will remove them. I also discovered that the code editor remove the quotes when there are no space in the string:

        Frame label="Radiateur" {
            Switch icon="dimmablelight" item=ZWaveNode033ZMNHJDFlushPilot_Dimmer label="Mode chauffage" mappings=[5=Arret,15="Hors gel",25=Eco,35="Confort -2°C",45="Confort -1°C",75=Confort]
            Text item=none
            Default icon="dimmablelight" item=ZWaveNode033ZMNHJDFlushPilot_Dimmer label="Fil Pilote"
        }

If I change:

75=Confort

by

75=“Confort”

as it should be.

When I save the sitemap and reload it, the two quotes disappeared but the code editor does not complain.

However, the sitemap works perfectly despite this.

Anyone faced such issue before ?