What we are looking to do is to determine if, not establish that, there are multiple checks (sorry to go all grammar hammer on you but it is an important distinction). Here is why I find your data not acceptable to answer this questions:
IF there are multiple checks happening the variables that could be observed are much greater that what you showed. Lets say that each debuff gets applied separatly (in an order of progression). Debuff #1 could get resisted by tenacity check causing no debuff application, causing no % chance of cleanse OR Debuff #1 could pass through tenacity check and still get applied due to cleanse chance failure. Then Debuff #2 and #3 and #4 go through the same process. If debuff 1, 2 and 3 all get applied and cleanse fails but then works on debuff 4 there would be nothing showing on the target at the end. Or the cleanse could happen on check 2 or 3 but fail on 4 so you would see only those debuffs that were ordered last.
Her zeta does not help her resist, It removes all existing debuffs on her. Without some dev feedback on what mechanics are actually at work behind the scenes here, it would be nearly impossible to tell whether any empirical data shows anything other than what you are predisposed to believe.
To paraphrase David Eddings - No man has ever used logic to prove something they didn't already believe.
