Panda 1.0 (415): markdown saving bug?

Testing version:
Panda Version 1.0 (415), Catalina 10.15.4
What were you doing:
Launch Panda
Create new file (Cmd+n)
Saving newly created empty file (Cmd+s) - the file is saved as markdown


Open saved file (Cmd+o) - the file is greyed out.

Here is what I see in Terminal:

mdls /Users/valerykondakoff/Documents/Untitled 
_kMDItemDisplayNameWithExtensions      = "Untitled"
kMDItemContentCreationDate             = 2020-05-06 21:26:10 +0000
kMDItemContentCreationDate_Ranking     = 2020-05-06 00:00:00 +0000
kMDItemContentModificationDate         = 2020-05-06 21:26:10 +0000
kMDItemContentModificationDate_Ranking = 2020-05-06 00:00:00 +0000
kMDItemContentType                     = "public.data"
kMDItemContentTypeTree                 = (
    "public.data",
    "public.item"
)
kMDItemDateAdded                       = 2020-05-06 21:26:10 +0000
kMDItemDateAdded_Ranking               = 2020-05-06 00:00:00 +0000
kMDItemDisplayName                     = "Untitled"
kMDItemDocumentIdentifier              = 3316
kMDItemFSContentChangeDate             = 2020-05-06 21:26:10 +0000
kMDItemFSCreationDate                  = 2020-05-06 21:26:10 +0000
kMDItemFSCreatorCode                   = ""
kMDItemFSFinderFlags                   = 0
kMDItemFSHasCustomIcon                 = 0
kMDItemFSInvisible                     = 0
kMDItemFSIsExtensionHidden             = 0
kMDItemFSIsStationery                  = 0
kMDItemFSLabel                         = 0
kMDItemFSName                          = "Untitled"
kMDItemFSNodeCount                     = 0
kMDItemFSOwnerGroupID                  = 20
kMDItemFSOwnerUserID                   = 501
kMDItemFSSize                          = 0
kMDItemFSTypeCode                      = ""
kMDItemInterestingDate_Ranking         = 2020-05-06 00:00:00 +0000
kMDItemKind                            = "Документ"
kMDItemLastUsedDate                    = 2020-05-06 21:26:44 +0000
kMDItemLastUsedDate_Ranking            = 2020-05-06 00:00:00 +0000
kMDItemLogicalSize                     = 0
kMDItemPhysicalSize                    = 0
kMDItemUseCount                        = 4
kMDItemUsedDates                       = (
    "2020-05-06 21:00:00 +0000"
)
kMDItemUserCreatedDate                 = (
    "2020-05-06 21:26:10 +0000"
)
kMDItemUserCreatedUserHandle           = (
    501
)

Markdown saving bug or something is wrong with my system?

Nothing changes if I manually add .md extension when saving file: there is still the same error.