@burnout426 I have download and installed the latest version of Opera (Developer 70.0.3693.0).
There is no such bug here, and all texts are displayed correctly, and also it is correctly in its italic style, without any problem.
I think this "correct approach" should be preserved, and also be applied to other existing erroneous versions of Opera browser, which may have such a bug.
Thanks again, Hooman Mallahzadeh