The latter developed stealth bubble technology of the 21st century suffered from a flaw that have never been countered due to the nature of the technology are that if stealth tanks run over infantry they will temporarily reveal itself, units and structures firing will also temporarily decloak. Also, all stealthed units can be detected with sufficiently advanced sensors (which are rare, due to their cost and sophistication). If a stealth vehicle is heavily damaged it will have a hard time cloaking.