Existence of a space with disjoint tightness but without ODT
Determine whether there exists a topological space that has disjoint tightness—meaning that for every subset A ⊆ X and every point x that is an accumulation point of A, there exist subsets A1, A2 ⊆ A with A1 ∩ A2 = ∅ such that x is an accumulation point of both A1 and A2—but does not have open disjoint tightness (ODT), where ODT requires that for every open set U ⊆ X and every point x ∈ U there exist disjoint open sets U1, U2 ⊆ U such that x is an accumulation point of both U1 and U2.
References
Question 6.1. Is there a space that has disjoint tightness and does not have ODT?
— On resolvability and tightness in uncountable spaces
(2402.11213 - Lipin, 17 Feb 2024) in Question 6.1, Section 6