I have weird behavior with custom linters

[bionic-ido]

I have written a custom linter, similar to the example presented with the TODO analyzer, only a bit different (checking against a different regex).
I then did some testing to run it locally against my code, and found that it found a couple of TODO's that did not match the requested format, which so far, so good.
I then played with it a bit, and found out a couple of weird behaviors that I hoped someone could make sense of:

1. If I am running only my own custom linter with everything else disabled, for some reason it doesn't really run it, and instead fails on varchecks that it for some reason doesn't manage to pass properly. However, if I add any other linter (even if it is a second custom linter), then suddenly they both run properly.
2. If I add to the message of the report of my custom todo linter, the comment text itself (so that instead of being the same message for all of them aside from the position, it is pretty much unique as it also contains the todo itself), then it for some reason makes it match to more locations in code (which I would want it to complain about even if I didn't put the message into it). I assume for some reason when the message is the same, some logic that tries to avoid duplicates gets rid of some legitimate, non-duplicate places (as it is, not duplicates, as they are in entirely different directories, files and packages, and even lines within the files).
3. This one might be okay, but if a specific line is reported by 2 different custom analyzers (with different messages), only one of the messages is shown at the end (seems like the first one to run).

Thanks in advance for any help.

The example code for the custom todo plugin if it is relevant:

package todo

import (
   "go/ast"
   "golang.org/x/tools/go/analysis"
   "regexp"
   "strings"
)

var validTodoRegex = regexp.MustCompile(`\/\/ ?TODO:? http[^ ]*BIOC-[0-9]+`)

var Analyzer = &analysis.Analyzer{
   Name: "todo",
   Doc:  "finds todos without issue links",
   Run:  run,
}

func run(pass *analysis.Pass) (interface{}, error) {
   for _, file := range pass.Files {
   	ast.Inspect(file, func(n ast.Node) bool {
   		if comment, ok := n.(*ast.Comment); ok {
   			if !validTodoRegex.MatchString(comment.Text) {
   				if strings.Contains(strings.ToLower(comment.Text), "todo") {
   					pass.Report(analysis.Diagnostic{
   						Pos:      comment.Pos(),
   						End:      comment.End(),
   						Category: "todo",
   						//Message:  fmt.Sprintf("'%s' has no issue link. e.g. '// TODO https://.../BIOC-XXXX'", comment.Text),
   						Message: "todo comment has no issue link. e.g. '// TODO https://.../BIOC-XXXX'",
   					})
   				}
   			}
   		}

   		return true
   	})
   }
   return nil, nil
}