Features not accessible and underline preview

Something in my CALT feature is preventing me from activating the features in the edit view. The features compile fine, and when CALT is disabled, I can access the features pane at the bottom left. But when CALT is enabled and features are compiled, features are not accessible.

CALT code:

lookup thaiNarrowMarks {
lookupflag UseMarkFilteringSet @thaiAboveMarks;
sub @aboveVowels @toneMarks' by @toneMarksUp;
####sub [poPla-thai foFa-thai foFan-thai] @thaiBelowMarks maiEk-thai' by maiEk-thai.narrow;
sub [poPla-thai foFa-thai foFan-thai] [maiEk-thai maiTho-thai maiTri-thai maiChattawa-thai maitaikhu-thai]' by [maiEk-thai.narrow maiTho-thai.narrow maiTri-thai.narrow maiChattawa-thai.narrow maitaikhu-thai.narrow];
} thaiNarrowMarks;

lookup nikhahit {
sub @toneMarks' [nikhahit-thai niggahita-lao] by @toneMarksUp;
sub [nikhahit-thai niggahita-lao] @toneMarks' by @toneMarksUp;
} nikhahit;

lookup laoAboveVowelsShift {# substitutes centred maiKan and maiKong when used as part of a complex vowel with preceding signs
	lookupflag UseMarkFilteringSet @laoShiftingMarks;
	# script lao;
		sub @laoPrebaseVowels [poPa-lao foFon-lao foFai-lao yoYa-lao] [maiKanVowel-lao maiKonVowel-lao maiKanVowel-lao.centred maiKonVowel-lao.centred]' by [maiKanVowel-lao.centred.ascender maiKonVowel-lao.centred.ascender maiKanVowel-lao.centred.ascender maiKonVowel-lao.centred.ascender];
		sub @laoPrebaseVowels @laoBases [maiKanVowel-lao maiKonVowel-lao]' by [maiKanVowel-lao.centred maiKonVowel-lao.centred];
		sub @laoPrebaseVowels [poPa-lao foFon-lao foFai-lao yoYa-lao] loVowel-lao [maiKanVowel-lao maiKonVowel-lao maiKanVowel-lao.centred maiKonVowel-lao.centred]' by [maiKanVowel-lao.centred.ascender maiKonVowel-lao.centred.ascender maiKanVowel-lao.centred.ascender maiKonVowel-lao.centred.ascender ];
		sub @laoPrebaseVowels @laoBases loVowel-lao  [maiKanVowel-lao maiKonVowel-lao]' by [maiKanVowel-lao.centred maiKonVowel-lao.centred];
		sub niggahita-lao' [maiEk-lao maiEk-lao.small maiTho-lao maiTho-lao.small maiTi-lao maiTi-lao.small maiCatawa-lao maiCatawa-lao.small] aaVowel-lao by niggahita-lao.right;
		sub niggahita-lao' aaVowel-lao by niggahita-lao.right;
		} laoAboveVowelsShift;

lookup burmesePostVowels {
sub [yaMedial-myanmar waMedial-myanmar] [uMark-myanmar uuMark-myanmar]' by [uMark-myanmar.post uuMark-myanmar.post];
sub [jha-myanmar tta-myanmar ttha-myanmar dda-myanmar lla-myanmar] [uMark-myanmar uuMark-myanmar]' by [uMark-myanmar.post uuMark-myanmar.post];
} burmesePostVowels;

lookup burmeseMedialLigs {
sub yaMedial-myanmar waMedial-myanmar haMedial-myanmar by yaMedial_waMedial_haMedial-myanmar;
sub yaMedial-myanmar waMedial-myanmar by yaMedial_waMedial-myanmar;
sub yaMedial-myanmar haMedial-myanmar by yaMedial_haMedial-myanmar;
sub yaMedial-myanmar iMark-myanmar uMark-myanmar by yaMedial_iMark_uMark-myanmar;
} burmeseMedialLigs;

lookup burmeseHaMedial {
sub nnya-myanmar haMedial-myanmar' by haMedial-myanmar.short;
} burmeseHaMedial;

lookup medialRaLigs {
lookupflag UseMarkFilteringSet @belowMarksMymr;
sub raMedial-myanmar' @basesMymr uMark-myanmar by raMedial_uMark-myanmar;
sub raMedial_uMark-myanmar @basesMymr uMark-myanmar' by noGlyph;
} medialRaLigs;

lookup medialRaWidth {
sub raMedial-myanmar' @wideBases by raMedial-myanmar.w2;
} medialRaWidth;

lookup medialRaTTBT {
lookupflag 0;
sub raMedial-myanmar' @basesMymr @aboveMarksMymr @belowMarksMymr by raMedial-myanmar.tt.bt;
sub raMedial-myanmar.w2' @basesMymr @aboveMarksMymr @belowMarksMymr by raMedial-myanmar.tt.bt.w2;
sub raMedial-myanmar' @basesMymr @belowMarksMymr @aboveMarksMymr by raMedial-myanmar.tt.bt;
sub raMedial-myanmar.w2' @basesMymr @belowMarksMymr @aboveMarksMymr by raMedial-myanmar.tt.bt.w2;
} medialRaTTBT;

lookup medialRaTT {
sub raMedial-myanmar' @basesMymr @aboveMarksMymr by raMedial-myanmar.tt;
sub raMedial-myanmar.w2' @basesMymr @aboveMarksMymr by raMedial-myanmar.tt.w2;
} medialRaTT;

lookup medialRaBT {
sub raMedial-myanmar' @basesMymr @belowMarksMymr by raMedial-myanmar.bt;
sub raMedial-myanmar.w2' @basesMymr @belowMarksMymr by raMedial-myanmar.bt.w2;
} medialRaBT;

lookup burmeseAa_asat {
sub aaTall-myanmar asat-myanmar by aaTall_asat-myanmar;
} burmeseAa_asat;

lookup medialHaligs {
lookupflag UseMarkFilteringSet @belowMarksMymr;
sub waMedial-myanmar haMedial-myanmar by waMedial_haMedial-myanmar;
sub haMedial-myanmar uMark-myanmar by haMedial_uMark-myanmar;
sub haMedial-myanmar uuMark-myanmar by haMedial_uuMark-myanmar;
} medialHaligs;

lookup burmeseAlternateBases {
#### sub na-myanmar' @aboveMarksMymr @belowMarksMymr by na-myanmar.short;
sub na-myanmar' @belowMarksMymr by na-myanmar.short;
sub ra-myanmar' haMedial-myanmar by ra-myanmar.straight;
sub ra-myanmar' @belowMarksMymr by ra-myanmar.short;
sub @raMedials @basesMymr haMedial-myanmar' by haMedial-myanmar.shortshift;
} burmeseAlternateBases;

Separately, clicking the underline preview is not having any effect in any font even when underline values are defined.

Can you send me the file?

Yes ok thanks.