Switch power cuts off when i insert or remove joycon in tablet

hi guys. i got this weird problem,
i play mario party. and 1-2 switch. they require the controllers be handheld while the tablet is on the dock.
when i insert or remove the joycon into the rail (Right side), the tablet power cuts off.
the tablet power is 90+% (docked) the joycon power is low to fully charged.
do i need to tighten some screws or something?
any controller sliding on or off does this.( irregardless of charge status on the joycon)
i play on handhelpd mode, no problems, unless i remove the joycon.
your advice is highly appreciated.
many thanks,

I have the same issue ((
Do you found solution?

Does it work wireless if you boot the console with them already removed?

I would check the connector pins and verify the integrity of the flat cable. You might have some pins making contact with ground and that causes the switch to turn off. Also clean the motherboard connector using some IPA