I started getting random block misses when I upgraded to version 0.19.1 and 0.19.2, after looking into it I realized my 16Gb Ram server was getting consumed almost to 100% and this is on a node with only the witness plug-in enabled.
To avoid this problem, I decided to upgrade my server to 24 GB, I will report back on findings but I expect/hope that the problem will be fixed.
If you are thinking on running a node, please take RAM usage into consideration, I have found OVH to be a cheap option but not always stable, you could also check out 
Running your own node can be a pain, feel free to ask me any questions…