I have reason to believe that the tongues spoken at Pentecost were intelligible languages and those mentioned in 1 Cor 14 seemed to describe some fervently ecstatic and sincere utterances not necessarily intelligible to listeners or even the speakers themselves and require interpretation.
As shown from the chart, if we lump all the conflicting evidence to form a single opinion or belief, either extreme of cessation of tongues and the continuation of this gift is questionable.
Could it be the former had ceased while the latter gift continued ?
I had first hand experience of my loved one with the latter gift of tongues in praying for a sick person once and convicting him to believe in our Lord Jesus. It seemed to be one off and she did not have that gift anymore so far. I believe it was a desperate and sincere utterance due to lack of words to pray sincerely for the sick. The sick person was so cut to the heart that he wanted to be baptized immediately and did that later in the day. And he went to the Lord a few days later. Would I doubt that the Holy Spirit was present to convict the sick man to have faith ? If it was so, what to make of the utterance of my loved one ?
(Martin Luther, the champion of sola scriptura, said this, “The signs here spoken of (Mark 16:17-18) are to be used according to need. When the need arises, and the gospel is hard pressed, then we must definitely do these signs, before we allow the gospel to be maligned and knocked down.” – Believer’s Bible Commentary.)
(Information gleaned from Spiritual Maturity by J Oswald Sanders)