FTD version 6.2.2.2 was released Feb. 26th and contains many bug fixes, but I did not see this particular bug referenced in the release notes.
Although, this bug is worded sort of weird as the title references the 2100 series, "FP2100 FTD/ASA might report failure due to MIO-blade heartbeat failure", but in the product description in the bug details it only references ASA 5500x series firewalls which is obviously a totally different type of ASA.
I'd recommend applying the new 6.2.2.2 patch and see if that helps. Here's a link to the release notes: https://www.cisco.com/c/en/us/td/docs/security/firepower/622/622x/relnotes/Firepower_Relase_Notes_622x/Firepower_Relase_Notes_622x_chapter_01001.html
Thanks!