That's nonsense, you do not have to stop HRT for a bit of spotting.
Depending on how long it is since your last bleed the appropriate management would be;
1/. do nothing/observation only if you are still in perimenopause (<12m since last bleed) as irregular bleeding is common in this stage
2/.increase progestogen in the first instance in a low risk postmenopausal woman (>12m since last bleed).
3/. if any concerns or persistent bleeding, refer for scan +/- hysteroscopy.
None of these require you to come off HRT.
Up to date guidelines are available for clinicians on this however not all are aware and we often have to advocate for ourselves.
Other causes of spotting/bleeding should also be excluded eg vaginal atrophy, check cervical screening up to date.