Protiodesilylation of terminal alkynes method?

Are u using a lot of K2CO3? If i recall the desilylation goes with just catalytic base. Perhaps drop the amount, maybe even chill it too

Makes sense you’re seeing nucleophilic aromatic substitution. Tbaf or KF may yield better results

I remember doing this TMS deprotection with KF in DMF. The solubility of KF in DMF is not great, but it's sufficient.

2 equivs of KF + 1 equiv of AcOH in acetonitrile-water. You can also use acetone-water instead