In this paper, we examine how online teaching assistants (OLTAs) interact with students in terms of affective, behavioral, and cognitive support and the influence of OLTA training on these interactions. Through a thematic network analysis, using a tracking instrument and semi-structured interviews with 10 OLTAs, we examined how online university students are supported based on the quantity and quality of interactions with OLTAs, and how training contributes to interactions. Our research addressed two key questions: (1) How do OLTAs support learners in the quantity and quality of interactions? and (2) How does OLTA training around affective and behavioral support influence OLTA interactions with students? To identify support types OLTAs should provide students, we employed the academic communities of engagement framework. Our findings indicate OLTAs offer varying degrees of support, with discrepancies in the amount and quality of interactions. Furthermore, the training program impacts OLTAs, although its specific role remains unclear.