Autocomplete disappears after typing

[kjgoodrick]

Issue Type: Bug

Describe the bug
Autocomplete dissappears after typing in LaTex begin environments. Works after disabling vim.

To Reproduce
1.) Create basic latex file e.g.:

\documentclass{article}
\begin{document}

\end{document}

2.) Inside document type \begin and press tab to autocomplete begin environment

3.) Type any characters and autocomplete will disappear.

Expected behavior
Autocomplete should stay open and filter suggestions as you type.

Screenshots
Behavior with vim enabled:

Behavior without vim enabled:

Extension version: 1.12.4
VS Code version: Code 1.41.1 (26076a4de974ead31f97692a0d32f90d735645c0, 2019-12-18T14:58:56.166Z)
OS version: Windows_NT x64 10.0.18363

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz (4 x 3300)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off surface_control: disabled_off surface_synchronization: enabled_on video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	23.95GB (10.48GB free)
Process Argv
Screen Reader	no
VM	0%

[cvaldev]

This appears to be caused by the multicursor, I see the same behaviour in other languages and it behaves as expected when there is a single cursor.