Sounds like that's an issue with the wallet's APIs, the network is distributed. If it continues, you can import your SLP wallet's seed words into Electron Cash SLP (desktop).
Haven't used the desktop for 4 years 😄. Today they updated the Bitcoin.com Android app. Nothing changed.
Out of date desktop is no prob as long as it doesn't have viruses. Write down your seed words and maybe try a fresh reinstall of the wallet using seed or another device if possible.
