There are so many reasons for this you'd almost need a textbook to explain them all (the type of oil, the type of balls being used, the revs with which the bowlers throw them, too many people playing the same line, heavy, but shorter oil, too much open play before league, etc). As with many conditions in bowling and life, why ask why unless it helps you towards a solution. The most important thing is to recognize it and deal with it as you have. Good for you!
The TA is supposed to be one of those newer coverstocks like on the Rule and the Bully balls and the Brunswick Activators which are almost particle-like in their reactions and oil handling ability. So you must be having a lot of carrydown for this ball not to handle it (unless you have it polished, of course).
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"When we choose an action,
we also choose the consequences of that action.