Slot and Howe have exchanged text messages in the past, but they have gone quiet since Liverpool attempted to sign Isak from Newcastle.
Before their teams' match at St James' Park, Slot was asked if the drama had affected his relationship with Howe.
"I don't know," Slot replied.
"The only manager I've ever texted with was Eddie Howe in the Premier League. In Holland, I texted with a few more managers, but after the League Cup final, we exchanged a few messages."
Slot continued, "If I see him, I will be the same as I was last year, and I expect nothing different from him as well. On a higher level, I have no clue."
Slot expressed his sympathy for Howe, describing him as a "great human being" who is "always polite."
Slot also praised Howe's honesty and politeness, saying, "For the rest, I don't need to have sympathy for a manager who has so many good players in his squad."
However, Slot's comments were also lighthearted, as he joked that Howe's team still had many talented players, including Anthony Gordon and Jacob Murphy.
Slot concluded, "I think I like him, and I don't think it will be a surprise to anyone if eventually he leads the national team of England."
He described Howe as a "good human being" and a "very good manager."
Slot's comments suggest that he values his relationship with Howe and does not believe the Isak saga has damaged their friendship.