Can a Kiss investor (debt version) ask for its money back?

Hello HN, I write because we are currently going through a rough moment just after starting to get better traction results. The thing is we have an institutional investor who previously told us they would likely invest in future rounds, and might even be interested in eventually acquiring us. Everything was great with them. But after covid they decided they were pulling out of all their investments outside of their core business area, and we are outside of their core business. We signed the debt version of a KISS, and we are wondering if this entitles them to actually get their money back. Our lawyers at the time told us it was not the case, but with the current situation we want to be completely sure. We have not been able to find many resources on the topic, but the ones we have found either say (i) it's not a real debt or (ii) it is repayable after the maturity date. Any kind of information on the topic would be really appreciated. Thank you in advance and have a great rest of your weekend!