I have usually used Cortland 444 lines. This fall my 4 wt DT died after 6 or 7 years of hard work. I needed to get a new line and could not find a local shop that had a Cortland DT. So I bought a SA Mastery Series - Trout 4 wt DT. I have only fished it once. It cast fine but the tip refused to stay afloat. I cleaned and dried it but after a short while it was down again. A bit of Loon Aquel would float it for a bit, but soon it would go under again. Is this a problem with the SA lines? Was it because it was under 30 degrees? Have I got a bad line or am I just expecting too much? Any insights are appreciated.

David