The issue is indirectly caused by setting the title from the primary prompt PS1, which is reprinted on each window resize.
You can "fix" it for yourself by removing the setting of the title from PS1 (which goes like "\[\e]0;whatever_the_new_title_is\a\]"). You can add something equivalent to PROMPT_COMMAND if you wish.
The issue is indirectly caused by setting the title from the primary prompt PS1, which is reprinted on each window resize.
You can "fix" it for yourself by removing the setting of the title from PS1 (which goes like "\[\e]0; whatever_ the_new_ title_is\ a\]"). You can add something equivalent to PROMPT_COMMAND if you wish.