Using gopls as goimports replacement produce wrong formatting

[powerman]

What did you do? (required: The issue will be closed when not provided)

let g:go_fmt_command = 'gopls'
let g:go_imports_autosave = 1
let g:go_imports_mode = 'gopls'

Open and save file with this contents:

package main
func F(*testing.T, time.Time) {}

The result will be:

package main
import (
	"testing"
	"time"
)
func F(*testing.T, time.Time) {}

which is weird because gopls imports executed in console produce a bit different result:

package main

import (
	"testing"
	"time"
)
func F(*testing.T, time.Time) {}

What did you expect to happen?

vim-go output should match gopls imports's one.
A bit more details are in #2993 (comment)

What happened instead?

vim-go output differs from gopls imports.

Configuration (MUST fill this out):

vim-go version:

bf2dd52

vimrc you used to reproduce:

vimrc

let g:go_fmt_command = 'gopls'
let g:go_imports_autosave = 1
let g:go_imports_mode = 'gopls'

Vim version (first three lines from :version):

VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Jul 20 2020 21:21:41)
Included patches: 1-360
Modified by Gentoo-8.2.0360

Go version (go version):

go version go1.15.1 linux/amd64

Go environment

go env Output:

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/powerman/.cache/go-build"
GOENV="/home/powerman/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/powerman/go/pkg/mod"
GONOPROXY="github.com/dentalcpdpro,github.com/mtgroupit,gitlab.qarea.org"
GONOSUMDB="github.com/dentalcpdpro,github.com/mtgroupit,gitlab.qarea.org"
GOOS="linux"
GOPATH="/home/powerman/go"
GOPRIVATE="github.com/dentalcpdpro,github.com/mtgroupit,gitlab.qarea.org"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="x86_64-pc-linux-gnu-gcc"
CXX="x86_64-pc-linux-gnu-g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build494885945=/tmp/go-build -gno-record-gcc-switches"

gopls version

gopls version Output:

golang.org/x/tools/gopls 0.4.4
    golang.org/x/tools/[email protected] h1:8djGYsaZ0ByP0vaXg4T+mnyfDcHpWKSZ+tpQSGv9ahk=