It looked more like a scan in progress than a warning. The big thing that sent up the red flag for me was the new icon showing up but the fact that it didn't have an uninstall option was weird. Is that grey M (styled like malware byte's) icon yours for anti-ransomware? I waited a day to see if it would do this same thing but that never happened and nothing came up on MalwareBytes scans. Sorry I can't send any reports I've already done a factory reset.
I have had Malwarebytes on my phone (A Lenovo Moto Z Play) for a few weeks now and haven't had any issues but while using the podkicker app something looking like the app's scanner and saying Malware bytes on it came up saying that it was checking for Ransomware and had a close button on the bottom which looked a little bit off so I tried going back or opening the launcher and it wouldn't let me do either. At most it would flicker for a fraction of a second and I could see podkicker but then would come back. I had to do a hard reset of the phone to get out of it. When it started