Hello catalin.chivu,

I may not really understand, what you would like to do.
Would you like to set a PLC-bit with the "Press Left"-event,
and reset the same Plc-bit with the "Release Left"-event,
of the same button.

This does not work with a direct connection.

You need to use C-Aktion or VBS-Aktion with WAIT-functions.

see manual:
"SIMATIC HMI WinCC V7.5 SP2 WinCC Information System"
"SetTag or SetTagWait?"

https://support.industry.siemens.com/cs/ww/en/view/109792585/45885119243

"Example: Writing tag values"
"Synchronous writing"

https://support.industry.siemens.com/cs/ww/en/view/109792585/118089674379

Regards

Georg Berghof