The 8 kinds of vicikicha

Recently, I read a Dhamma Talk book by The Late Ven. Mogok Sayadaw.

In one of the Dhamma talks, he mentioned about the 8 kinds of doubt or scepticism or Vicikicha.

Everything seem as usual except when he mentions about the 3rd kind of Vicikicha ie. the Ariya Sangha not just Sangha. I startled a little bit although I understand what he meant on his Dhamma talk in 1956, as it is a reality that current Sangha full of people with different motives in using the Saffron Robes. Even the Buddha already told us about the many kind of monks the Sangha will have later.

Can give more context?

What does the doubt mean?

Does it mean to regard all monastics as ariya sangha? So that doubt that any monastic is not ariya sangha is considered as doubt?

Or is it with regards to the object of refuge, that is doubt if we take refuge in the ariya sangha or Bhikkhu/Bhikkhuni Sangha?

Bhante @NgXinZhao the pdf can be found for your information.

Mogok Sayadaw - Doubt & Knowledge.pdf (61.0 KB)

The book is about 800 pages (?) and I send only 2 pages of 1959 Dhamma talk