Site pages render super slow at random moments

[krmrtrzv]

Hello, I observe strange behaviour of one website with K2ForJ4 content.
Debug console says a page loaded for 143.66 s. All queries are OK, but one:
"afterRenderComponent com_k2 (1.17MB) (143.49s)"
I checked everything and can not figure out what might be the problem.
J version is 4.4.8, the content uses FaLang for content translations. Bilingual bg-BG/en-EN.
This started only last month and affects only the last 6 K2 Items published. Checked their contents many times no problems. The site is live and I can provide URLs in DM.