Dear yupenghe,
In looking through DMRs in IGV, I'm finding some regions that look like they should be called DMRs, but there were not (see screenshot example).

DMRfind code below was executed:
methylpy DMRfind --allc-files results_WGBS/methylpy/processing/allc_1.tsv.gz results_WGBS/methylpy/processing/allc_2.tsv.gz --num-procs 64 --output-prefix results_WGBS/methylpy/DMR4/dmr6 &> results_WGBS/methylpy/dmr6.log
.bw files were generated by methylpy allc-to-bigwig with default parameters.
Thanks.