Only an issue on Firefox for Android Nightly, but I have to set gfx.downloadable_fonts.otl_validation to false when using the latest Tabler Icons otherwise they are not displayed, and return errors in the remote console like this:

downloadable font: GSUB: Bad ligature offset 3218 for ligature 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: GSUB: Failed to parse ligature set 18 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: Layout: Failed to parse lookup subtable 3 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: Layout: Failed to parse subtable 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: Layout: Failed to parse lookup 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: GSUB: Failed to parse lookup list table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: GSUB: Failed to parse table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: rejected by sanitizer (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:1) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff2?v2.1.2
downloadable font: GSUB: Bad ligature offset 3218 for ligature 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: GSUB: Failed to parse ligature set 18 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: Layout: Failed to parse lookup subtable 3 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: Layout: Failed to parse subtable 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: Layout: Failed to parse lookup 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: GSUB: Failed to parse lookup list table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: GSUB: Failed to parse table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: rejected by sanitizer (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:2) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.woff?
downloadable font: GSUB: Bad ligature offset 3218 for ligature 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: GSUB: Failed to parse ligature set 18 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: Layout: Failed to parse lookup subtable 3 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: Layout: Failed to parse subtable 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: Layout: Failed to parse lookup 0 (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: GSUB: Failed to parse lookup list table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: GSUB: Failed to parse table (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2
downloadable font: rejected by sanitizer (font-family: "tabler-icons" style:normal weight:400 stretch:100 src index:3) source: https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@2.1.2/fonts/tabler-icons.ttf?v2.1.2 

There’s an open GitHub issue about the problem here but no fix yet.