I often quit Opera and wait until the space it used is released. Then I open it.
However today everytime I quit it (it's not a crash nor a forced quit), it reopens.

Your software is out of control and nothing is done about it

So tons of people have been reporting this bug for several years but nobody knows what it's due to

@leocg v89.0.4447.91 is the mos tup to date version for my system.

I often quit Opera and wait until the space it used is released. Then I open it.
However today everytime I quit it (it's not a crash nor a forced quit), it reopens.